Generalized and Localized Rashes

Rashes are a group of diseases that cause abnormal coloration and texture Texture Dermatologic Examination to the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions. The etiologies are numerous but can include irritation, allergens, infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease, or inflammatory conditions. Rashes that present in only 1 area of the body are called localized rashes. Generalized rashes occur diffusely throughout the body. Rashes can be classified by their distribution, configuration, and morphology. The diagnosis is often clinical and based on the patient’s history and physical exam findings. Management is dependent on identifying the correct condition and varies depending on the etiology.

Last updated: Oct 28, 2021

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Overview

Definition

A rash Rash Rocky Mountain Spotted Fever is an abnormal change in the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions’s color or texture Texture Dermatologic Examination.

Epidemiology

Etiology

The list of etiologies for rashes is long but can include irritants, allergens, infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease, and inflammatory conditions.

Classification

Rashes are described and classified based on certain characteristics, which can assist with forming a differential diagnosis when evaluating a patient.

Configuration

The configuration refers to the shape or outline of lesions.  

  • Circinate: round, circular
  • Arciform: forms a partial circle
  • Linear: appears straight 
  • Serpiginous: meandering appearance
  • Annular Annular Dermatologic Examination: round or circular with central clearing  
  • Target: a series of concentric rings 
  • Gyrate: a series of connecting arcs  
  • Zosteriform: appears to follow a dermatome Dermatome Spinal Disk Herniation
Rash configurations

Visualization of different rash Rash Rocky Mountain Spotted Fever configurations

Image by Lecturio.

Morphology

The morphology is based on the size and consistency Consistency Dermatologic Examination of the lesions.

  • Flat lesions:
    • Macule: nonpalpable lesion < 1 cm in diameter
    • Patch: nonpalpable lesion > 1 cm in diameter
  • Raised lesions:
  • Blistering lesions:
  • Disruption of the epidermis Epidermis The external, nonvascular layer of the skin. It is made up, from within outward, of five layers of epithelium: (1) basal layer (stratum basale epidermidis); (2) spinous layer (stratum spinosum epidermidis); (3) granular layer (stratum granulosum epidermidis); (4) clear layer (stratum lucidum epidermidis); and (5) horny layer (stratum corneum epidermidis). Skin: Structure and Functions:
    • Erosion: partial-thickness loss of the epidermis Epidermis The external, nonvascular layer of the skin. It is made up, from within outward, of five layers of epithelium: (1) basal layer (stratum basale epidermidis); (2) spinous layer (stratum spinosum epidermidis); (3) granular layer (stratum granulosum epidermidis); (4) clear layer (stratum lucidum epidermidis); and (5) horny layer (stratum corneum epidermidis). Skin: Structure and Functions
    • Fissure: a crack Crack The purified, alkaloidal, extra-potent form of cocaine. It is smoked (free-based), injected intravenously, and orally ingested. Use of crack results in alterations in function of the cardiovascular system, the autonomic nervous system, the central nervous system, and the gastrointestinal system. The slang term ‘crack’ was derived from the crackling sound made upon igniting of this form of cocaine for smoking. Cocaine Use Disorder or split that extends into the dermis Dermis A layer of vascularized connective tissue underneath the epidermis. The surface of the dermis contains innervated papillae. Embedded in or beneath the dermis are sweat glands; hair follicles; and sebaceous glands. Skin: Structure and Functions
    • Ulcer: full-thickness loss of the epidermis Epidermis The external, nonvascular layer of the skin. It is made up, from within outward, of five layers of epithelium: (1) basal layer (stratum basale epidermidis); (2) spinous layer (stratum spinosum epidermidis); (3) granular layer (stratum granulosum epidermidis); (4) clear layer (stratum lucidum epidermidis); and (5) horny layer (stratum corneum epidermidis). Skin: Structure and Functions that extends into the dermis Dermis A layer of vascularized connective tissue underneath the epidermis. The surface of the dermis contains innervated papillae. Embedded in or beneath the dermis are sweat glands; hair follicles; and sebaceous glands. Skin: Structure and Functions
Rash morphology

Visualization of different rash Rash Rocky Mountain Spotted Fever morphologies

Image by Lecturio.
Rash morphology flowchart

Schematic to help differentiate different morphologies based on their size and characteristics

Image by Lecturio.

Secondary characteristics

  • Crust Crust Dried exudate of body fluids (blood, pus, or sebum) on an area of damaged skin Secondary Skin Lesions: dried exudate Exudate Exudates are fluids, cells, or other cellular substances that are slowly discharged from blood vessels usually from inflamed tissues. Pleural Effusion on the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions
  • Scale Scale Dermatologic Examination: flakes or plates of desiccated epidermis Epidermis The external, nonvascular layer of the skin. It is made up, from within outward, of five layers of epithelium: (1) basal layer (stratum basale epidermidis); (2) spinous layer (stratum spinosum epidermidis); (3) granular layer (stratum granulosum epidermidis); (4) clear layer (stratum lucidum epidermidis); and (5) horny layer (stratum corneum epidermidis). Skin: Structure and Functions
  • Lichenification Lichenification Atopic Dermatitis (Eczema): leathery thickening of the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions with exaggerated skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions markings
  • Excoriation Excoriation Mastitis: linear skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions erosions Erosions Corneal Abrasions, Erosion, and Ulcers, often caused by scratching
  • Edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema: swelling Swelling Inflammation of the tissue
  • Scar Scar Dermatologic Examination: fibrous Fibrous Fibrocystic Change tissue development after an injury

Distribution

  • Localized: Lesions are confined to a specific area.
  • Generalized: Lesions are dispersed throughout the body.
  • Symmetric: similarly affects both sides of the body
  • Asymmetric: unilateral or affects both sides of the body differently
  • Discrete: separate, distinct lesions
  • Grouped: clusters of lesions
  • Confluent (coalescing): Smaller lesions merge together.
  • Cleavage plane: Lesions are arranged along the lines of skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions tension.
Rash distribution

Visualization of different rash Rash Rocky Mountain Spotted Fever distributions

Image by Lecturio.

Clinical Presentation and Diagnosis

The diagnosis for many conditions is purely clinical and based on the patient’s history and physical exam.

History

  • Onset (including the location of initial onset)
  • Time frame:
    • Acute or chronic
    • Relapsing-remitting
  • Progression
  • Aggravating and alleviating factors
  • Associated symptoms:
    • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
    • Pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema)
    • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
    • Malaise Malaise Tick-borne Encephalitis Virus
    • Cough
  • Other pertinent history: 
Table: Summary of possible conditions based on patient’s history
Patient’s history Associated disease
Chronic illness
  • Dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema) herpetiformis
  • Seborrheic dermatitis Seborrheic dermatitis Seborrheic dermatitis is a common chronic, relapsing skin disorder that presents as erythematous plaques with greasy, yellow scales in susceptible areas (scalp, face, and trunk). Seborrheic dermatitis has a biphasic incidence, occurring in two peaks: first in infants, then in adolescence and early adulthood. Seborrheic Dermatitis
Contact with ill persons
  • 5th disease
  • Meningococcemia Meningococcemia Terminal Complement Pathway Deficiency
  • Rubella Rubella An acute infectious disease caused by the rubella virus. The virus enters the respiratory tract via airborne droplet and spreads to the lymphatic system. Rubella Virus
  • Roseola
  • Rubeola Rubeola Measles (also known as rubeola) is caused by a single-stranded, linear, negative-sense RNA virus of the family Paramyxoviridae. It is highly contagious and spreads by respiratory droplets or direct-contact transmission from an infected person. Typically a disease of childhood, measles classically starts with cough, coryza, and conjunctivitis, followed by a maculopapular rash. Measles Virus
  • Scarlet fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
  • Varicella
Drug exposure Exposure ABCDE Assessment
  • Lupus
  • Drug eruption
  • Urticaria Urticaria Urticaria is raised, well-circumscribed areas (wheals) of edema (swelling) and erythema (redness) involving the dermis and epidermis with associated pruritus (itch). Urticaria is not a single disease but rather is a reaction pattern representing cutaneous mast cell degranulation. Urticaria (Hives)
  • Stevens-Johnson syndrome Stevens-Johnson syndrome Stevens-Johnson syndrome (SJS) is a cutaneous, immune-mediated hypersensitivity reaction that is commonly triggered by medications, including antiepileptics and antibiotics. The condition runs on a spectrum with toxic epidermal necrolysis (TEN) based on the amount of body surface area (BSA) involved. Stevens-Johnson Syndrome
Occupational or environmental exposure Exposure ABCDE Assessment Contact dermatitis Contact dermatitis A type of acute or chronic skin reaction in which sensitivity is manifested by reactivity to materials or substances coming in contact with the skin. It may involve allergic or non-allergic mechanisms. Male Genitourinary Examination
Insect and arthropod exposure Exposure ABCDE Assessment
  • Insect bites
  • Lyme disease Lyme disease Lyme disease is a tick-borne infection caused by the gram-negative spirochete Borrelia burgdorferi. Lyme disease is transmitted by the black-legged Ixodes tick (known as a deer tick), which is only found in specific geographic regions. Patient presentation can vary depending on the stage of the disease and may include a characteristic erythema migrans rash. Lyme Disease
  • Rickettsialpox Rickettsialpox Rickettsia
  • Rocky Mountain spotted fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
  • Scabies Scabies Scabies is an infestation of the skin by the Sarcoptes scabiei mite, which presents most commonly with intense pruritus, characteristic linear burrows, and erythematous papules, particularly in the interdigital folds and the flexor aspects of the wrists. Scabies
Recent systemic symptoms
  • 5th disease
  • HIV HIV Anti-HIV Drugs acute exanthem Exanthem Diseases in which skin eruptions or rashes are a prominent manifestation. Classically, six such diseases were described with similar rashes; they were numbered in the order in which they were reported. Only the fourth (Duke’s disease), fifth (erythema infectiosum), and sixth (exanthema subitum) numeric designations survive as occasional synonyms in current terminology. Varicella-Zoster Virus/Chickenpox
  • Kawasaki disease Kawasaki disease An acute, febrile, mucocutaneous condition accompanied by swelling of cervical lymph nodes in infants and young children. The principal symptoms are fever, congestion of the ocular conjunctivae, reddening of the lips and oral cavity, protuberance of tongue papillae, and edema or erythema of the extremities. Kawasaki Disease
  • Meningococcemia Meningococcemia Terminal Complement Pathway Deficiency
  • Roseola
  • Rubella Rubella An acute infectious disease caused by the rubella virus. The virus enters the respiratory tract via airborne droplet and spreads to the lymphatic system. Rubella Virus
  • Rubeola Rubeola Measles (also known as rubeola) is caused by a single-stranded, linear, negative-sense RNA virus of the family Paramyxoviridae. It is highly contagious and spreads by respiratory droplets or direct-contact transmission from an infected person. Typically a disease of childhood, measles classically starts with cough, coryza, and conjunctivitis, followed by a maculopapular rash. Measles Virus
  • Scarlet fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
  • Varicella
Sexual history
  • HIV HIV Anti-HIV Drugs acute exanthem Exanthem Diseases in which skin eruptions or rashes are a prominent manifestation. Classically, six such diseases were described with similar rashes; they were numbered in the order in which they were reported. Only the fourth (Duke’s disease), fifth (erythema infectiosum), and sixth (exanthema subitum) numeric designations survive as occasional synonyms in current terminology. Varicella-Zoster Virus/Chickenpox
  • Secondary syphilis Secondary Syphilis Syphilis
  • Disseminated gonorrhea Gonorrhea Gonorrhea is a sexually transmitted infection (STI) caused by the gram-negative bacteria Neisseria gonorrhoeae (N. gonorrhoeae). Gonorrhea may be asymptomatic but commonly manifests as cervicitis or urethritis with less common presentations such as proctitis, conjunctivitis, or pharyngitis. Gonorrhea
Travel
  • Insect bites
  • Lyme disease Lyme disease Lyme disease is a tick-borne infection caused by the gram-negative spirochete Borrelia burgdorferi. Lyme disease is transmitted by the black-legged Ixodes tick (known as a deer tick), which is only found in specific geographic regions. Patient presentation can vary depending on the stage of the disease and may include a characteristic erythema migrans rash. Lyme Disease
  • Rickettsialpox Rickettsialpox Rickettsia
  • Rocky Mountain spotted fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
HIV HIV Anti-HIV Drugs: human immunodeficiency virus Human Immunodeficiency Virus Anti-HIV Drugs

Physical exam

A full skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions exam should be performed.

  • Appearance:
  • Distribution:
  • Palpation Palpation Application of fingers with light pressure to the surface of the body to determine consistency of parts beneath in physical diagnosis; includes palpation for determining the outlines of organs. Dermatologic Examination of lesions:
  • In patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with bullae Bullae Erythema Multiforme, check for Nikolsky sign Nikolsky Sign Dermatologic Examination:
    • Extension Extension Examination of the Upper Limbs of skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions blistering or sloughing by applying pressure
    • Demonstrates skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions detachment
  • In patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with plaques, check for Auspitz sign Auspitz Sign Psoriasis: pinpoint bleeding after scraping plaques
  • Other physical exam findings to evaluate for:
    • Vital signs
    • Lymphadenopathy Lymphadenopathy Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy
    • Conjunctivitis Conjunctivitis Conjunctivitis is a common inflammation of the bulbar and/or palpebral conjunctiva. It can be classified into infectious (mostly viral) and noninfectious conjunctivitis, which includes allergic causes. Patients commonly present with red eyes, increased tearing, burning, foreign body sensation, and photophobia. Conjunctivitis
    • Pharyngitis Pharyngitis Pharyngitis is an inflammation of the back of the throat (pharynx). Pharyngitis is usually caused by an upper respiratory tract infection, which is viral in most cases. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, and hoarseness. Pharyngitis
    • Heart murmur
    • Hepatosplenomegaly Hepatosplenomegaly Cytomegalovirus
    • Joint swelling Swelling Inflammation
    • Neurologic deficits Neurologic Deficits High-Risk Headaches

Testing

A diagnostic workup may be performed if the history and physical exam do not provide enough clues to the diagnosis. The differential diagnosis will dictate which studies should be performed.

  • Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma with microscopic examination:
    • There are no widely accepted guidelines with indications for skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma.
    • Immunofluorescence can be helpful.
  • Laboratory tests are indicated if there are systemic symptoms.
    • CBC → evaluate for eosinophilia Eosinophilia Abnormal increase of eosinophils in the blood, tissues or organs. Autosomal Dominant Hyperimmunoglobulin E Syndrome, neutrophilia, or thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia
    • Basic metabolic panel Basic Metabolic Panel Primary vs Secondary Headaches and liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy function panel → evaluate for systemic renal and hepatic involvement
    • ANAs → a good initial test if an autoimmune etiology is being considered
    • Serologic testing for various infectious Infectious Febrile Infant causes
  • Allergy Allergy An abnormal adaptive immune response that may or may not involve antigen-specific IgE Type I Hypersensitivity Reaction testing:
    • Patch testing
    • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions prick testing
    • Serum IgE IgE An immunoglobulin associated with mast cells. Overexpression has been associated with allergic hypersensitivity. Immunoglobulins: Types and Functions studies

Management

The management of a rash Rash Rocky Mountain Spotted Fever depends on the underlying condition. Many rashes will be self-limited and may not require any treatment.

  • Basic management:
    • Identify and avoid aggravating factors.
    • Supportive therapies:
      • Low-heat baths
      • Mild soaps
      • Emollients Emollients Oleaginous substances used topically to soothe, soften or protect skin or mucous membranes. They are used also as vehicles for other dermatologic agents. Pityriasis Rosea
      • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions moisturizers
  • Symptom management for pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and pruritis:
    • Acetaminophen Acetaminophen Acetaminophen is an over-the-counter nonopioid analgesic and antipyretic medication and the most commonly used analgesic worldwide. Despite the widespread use of acetaminophen, its mechanism of action is not entirely understood. Acetaminophen
    • NSAIDs NSAIDS Primary vs Secondary Headaches
    • Antihistamines Antihistamines Antihistamines are drugs that target histamine receptors, particularly H1 and H2 receptors. H1 antagonists are competitive and reversible inhibitors of H1 receptors. First-generation antihistamines cross the blood-brain barrier and can cause sedation. Antihistamines
  • For inflammatory conditions:
    • Infection should be ruled out.
    • Topical steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors:
      • Hydrocortisone Hydrocortisone The main glucocorticoid secreted by the adrenal cortex. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions. Immunosuppressants
      • Triamcinolone Triamcinolone A glucocorticoid given, as the free alcohol or in esterified form, orally, intramuscularly, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Glucocorticoids
      • Clobetasol Clobetasol A derivative of prednisolone with high glucocorticoid activity and low mineralocorticoid activity. Absorbed through the skin faster than fluocinonide, it is used topically in treatment of psoriasis but may cause marked adrenocortical suppression. Glucocorticoids
      • Betamethasone Betamethasone A glucocorticoid given orally, parenterally, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Its lack of mineralocorticoid properties makes betamethasone particularly suitable for treating cerebral edema and congenital adrenal hyperplasia. Glucocorticoids
    • Systemic steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors
  • For infectious Infectious Febrile Infant causes:
    • Antibiotics
    • Antifungals
    • Antivirals
  • Appropriate management for underlying systemic conditions

Comparison of Generalized Rashes

Noninfectious Noninfectious Febrile Infant conditions

Table: Summary of common noninfectious Noninfectious Febrile Infant generalized rashes
Condition Features Diagnosis Management
Atopic dermatitis Atopic Dermatitis Atopic dermatitis, also known as eczema, is a chronic, relapsing, pruritic, inflammatory skin disease that occurs more frequently in children, although adults can also be affected. The condition is often associated with elevated serum levels of IgE and a personal or family history of atopy. Skin dryness, erythema, oozing, crusting, and lichenification are present. Atopic Dermatitis (Eczema) ( eczema Eczema Atopic dermatitis, also known as eczema, is a chronic, relapsing, pruritic, inflammatory skin disease that occurs more frequently in children, although adults can also be affected. The condition is often associated with elevated serum levels of IgE and a personal or family history of atopy. Skin dryness, erythema, oozing, crusting, and lichenification are present. Atopic Dermatitis (Eczema))
  • Clinical diagnosis
  • Serum IgE IgE An immunoglobulin associated with mast cells. Overexpression has been associated with allergic hypersensitivity. Immunoglobulins: Types and Functions levels
  • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions prick tests
  • Patch tests
Drug eruption
  • Often an immune-mediated hypersensitivity reaction
  • Ranges in severity from urticaria Urticaria Urticaria is raised, well-circumscribed areas (wheals) of edema (swelling) and erythema (redness) involving the dermis and epidermis with associated pruritus (itch). Urticaria is not a single disease but rather is a reaction pattern representing cutaneous mast cell degranulation. Urticaria (Hives) and maculopapular Maculopapular Dermatologic Examination eruptions to EM, SJS SJS Stevens-Johnson syndrome (SJS) is a cutaneous, immune-mediated hypersensitivity reaction that is commonly triggered by medications, including antiepileptics and antibiotics. The condition runs on a spectrum with toxic epidermal necrolysis (TEN) based on the amount of body surface area (BSA) involved. Stevens-Johnson Syndrome, and TEN
Lesions may include:
  • Edematous wheals
  • Diffuse maculopapular Maculopapular Dermatologic Examination lesions
  • Target lesions
  • Cutaneous bullae Bullae Erythema Multiforme
  • Sloughing of skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions and mucosa
  • Systemic symptoms
  • Clinical diagnosis
  • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma is rarely needed.
  • Withdrawal of the offending drug
  • Symptomatic therapy
  • Supportive care
Pityriasis rosea Pityriasis rosea Pityriasis rosea is an acute, self-limited skin disease. The etiology is not known, and it commonly occurs in young adults. Patients initially present with a single, ovoid “herald patch.” This is followed by diffuse, pruritic, scaly, oval lesions over the trunk (often in a “Christmas tree” distribution on the back) and extremities. Pityriasis Rosea
  • Idiopathic Idiopathic Dermatomyositis
  • Single round, ovoid, salmon-colored patch (“ herald patch Herald Patch Pityriasis Rosea”)
  • Followed by a widespread exanthem Exanthem Diseases in which skin eruptions or rashes are a prominent manifestation. Classically, six such diseases were described with similar rashes; they were numbered in the order in which they were reported. Only the fourth (Duke’s disease), fifth (erythema infectiosum), and sixth (exanthema subitum) numeric designations survive as occasional synonyms in current terminology. Varicella-Zoster Virus/Chickenpox with scale Scale Dermatologic Examination
  • “Christmas tree” distribution on back
  • Pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema)
Clinical diagnosis
  • No intervention is needed.
  • Symptomatic management
Lichen planus Lichen planus Lichen planus (LP) is an idiopathic, cell-mediated inflammatory skin disease. It is characterized by pruritic, flat-topped, papular, purple skin lesions commonly found on the flexural surfaces of the extremities. Other areas affected include genitalia, nails, scalp, and mucous membranes. Lichen Planus
  • Idiopathic Idiopathic Dermatomyositis
  • Cell-mediated inflammatory disease
  • Flat-topped, papular, purple lesions
  • Pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema)
  • Includes genitalia, nails, scalp, and mucous membranes
  • Clinical diagnosis
  • Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma for confirmation
Topical steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors
Psoriasis Psoriasis Psoriasis is a common T-cell-mediated inflammatory skin condition. The etiology is unknown, but is thought to be due to genetic inheritance and environmental triggers. There are 4 major subtypes, with the most common form being chronic plaque psoriasis. Psoriasis
  • Cell-mediated inflammatory disease
  • Well-circumscribed, salmon-colored plaques
  • Silvery scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions
  • Seen on the scalp and extensor surfaces
  • Clinical diagnosis
  • Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma is rarely needed.
Local therapy:
  • Topical steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors
  • Calcitriol Calcitriol The physiologically active form of vitamin d. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (calcifediol). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption. Parathyroid Glands: Anatomy
  • Topical retinoids Retinoids Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products. Fat-soluble Vitamins and their Deficiencies
  • Phototherapy Phototherapy Treatment of disease by exposure to light, especially by variously concentrated light rays or specific wavelengths. Hyperbilirubinemia of the Newborn
Systemic therapy:
Note: Although pityriasis rosea Pityriasis rosea Pityriasis rosea is an acute, self-limited skin disease. The etiology is not known, and it commonly occurs in young adults. Patients initially present with a single, ovoid “herald patch.” This is followed by diffuse, pruritic, scaly, oval lesions over the trunk (often in a “Christmas tree” distribution on the back) and extremities. Pityriasis Rosea and lichen planus Lichen planus Lichen planus (LP) is an idiopathic, cell-mediated inflammatory skin disease. It is characterized by pruritic, flat-topped, papular, purple skin lesions commonly found on the flexural surfaces of the extremities. Other areas affected include genitalia, nails, scalp, and mucous membranes. Lichen Planus are considered idiopathic Idiopathic Dermatomyositis, they have been associated with certain viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology.
EM: erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion multiforme
SJS SJS Stevens-Johnson syndrome (SJS) is a cutaneous, immune-mediated hypersensitivity reaction that is commonly triggered by medications, including antiepileptics and antibiotics. The condition runs on a spectrum with toxic epidermal necrolysis (TEN) based on the amount of body surface area (BSA) involved. Stevens-Johnson Syndrome: Stevens-Johnson syndrome Stevens-Johnson syndrome Stevens-Johnson syndrome (SJS) is a cutaneous, immune-mediated hypersensitivity reaction that is commonly triggered by medications, including antiepileptics and antibiotics. The condition runs on a spectrum with toxic epidermal necrolysis (TEN) based on the amount of body surface area (BSA) involved. Stevens-Johnson Syndrome
TEN: toxic epidermal necrolysis Toxic Epidermal Necrolysis Stevens-Johnson Syndrome

Infectious Infectious Febrile Infant conditions

Table: Summary of common infectious Infectious Febrile Infant generalized rashes
Condition Features Diagnosis Management
Hand-foot-and-mouth disease
  • Caused by coxsackievirus Coxsackievirus Coxsackievirus is a member of a family of viruses called Picornaviridae and the genus Enterovirus. Coxsackieviruses are single-stranded, positive-sense RNA viruses, and are divided into coxsackie group A and B viruses. Both groups of viruses cause upper respiratory infections, rashes, aseptic meningitis, or encephalitis. Coxsackievirus type A
  • Painful oval-shaped vesicles Vesicles Female Genitourinary Examination on hands, feet, buttocks, and oral mucosa Oral mucosa Lining of the oral cavity, including mucosa on the gums; the palate; the lip; the cheek; floor of the mouth; and other structures. The mucosa is generally a nonkeratinized stratified squamous epithelium covering muscle, bone, or glands but can show varying degree of keratinization at specific locations. Stomatitis
  • Associated with fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
Clinical diagnosis Symptomatic treatment
Roseola infantum Roseola infantum An acute, short-lived, viral disease of infants and young children characterized by a high fever at onset that drops to normal after 3-4 days and the concomitant appearance of a macular or maculopapular rash that appears first on the trunk and then spreads to other areas. It is the sixth of the classical exanthematous diseases and is caused by HHV-6. Human Herpesvirus 6 and 7 ( exanthem Exanthem Diseases in which skin eruptions or rashes are a prominent manifestation. Classically, six such diseases were described with similar rashes; they were numbered in the order in which they were reported. Only the fourth (Duke’s disease), fifth (erythema infectiosum), and sixth (exanthema subitum) numeric designations survive as occasional synonyms in current terminology. Varicella-Zoster Virus/Chickenpox subitum)
  • Caused by HHV-6 HHV-6 Human herpesvirus (HHV)-6 and HHV-7 are similar double-stranded DNA viruses belonging to the Herpesviridae family. Human herpesviruses are ubiquitous and infections are commonly contracted during childhood. Human Herpesvirus 6 and 7 or -7
  • Rose-pink maculopapular Maculopapular Dermatologic Examination rash Rash Rocky Mountain Spotted Fever
  • Mostly on the chest and abdomen but the back, face, and extremities can be involved
  • Preceded by high fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever and cervical lymphadenopathy Lymphadenopathy Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy
Clinical diagnosis Symptomatic treatment
Measles Measles Measles (also known as rubeola) is caused by a single-stranded, linear, negative-sense RNA virus of the family Paramyxoviridae. It is highly contagious and spreads by respiratory droplets or direct-contact transmission from an infected person. Typically a disease of childhood, measles classically starts with cough, coryza, and conjunctivitis, followed by a maculopapular rash. Measles Virus ( rubeola Rubeola Measles (also known as rubeola) is caused by a single-stranded, linear, negative-sense RNA virus of the family Paramyxoviridae. It is highly contagious and spreads by respiratory droplets or direct-contact transmission from an infected person. Typically a disease of childhood, measles classically starts with cough, coryza, and conjunctivitis, followed by a maculopapular rash. Measles Virus)
  • Caused by the measles Measles Measles (also known as rubeola) is caused by a single-stranded, linear, negative-sense RNA virus of the family Paramyxoviridae. It is highly contagious and spreads by respiratory droplets or direct-contact transmission from an infected person. Typically a disease of childhood, measles classically starts with cough, coryza, and conjunctivitis, followed by a maculopapular rash. Measles Virus virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
  • Maculopapular Maculopapular Dermatologic Examination rash Rash Rocky Mountain Spotted Fever that begins on the face and spreads to the trunk and extremities
  • Koplik spots on the buccal membrane
  • Associated with a high fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, cough, coryza Coryza Inflammation of the nasal mucosa, the mucous membrane lining the nasal cavities. Rhinitis, and conjunctivitis Conjunctivitis Conjunctivitis is a common inflammation of the bulbar and/or palpebral conjunctiva. It can be classified into infectious (mostly viral) and noninfectious conjunctivitis, which includes allergic causes. Patients commonly present with red eyes, increased tearing, burning, foreign body sensation, and photophobia. Conjunctivitis
Clinical diagnosis Symptomatic treatment
Rubella Rubella An acute infectious disease caused by the rubella virus. The virus enters the respiratory tract via airborne droplet and spreads to the lymphatic system. Rubella Virus (German measles Measles Measles (also known as rubeola) is caused by a single-stranded, linear, negative-sense RNA virus of the family Paramyxoviridae. It is highly contagious and spreads by respiratory droplets or direct-contact transmission from an infected person. Typically a disease of childhood, measles classically starts with cough, coryza, and conjunctivitis, followed by a maculopapular rash. Measles Virus)
  • Caused by rubella Rubella An acute infectious disease caused by the rubella virus. The virus enters the respiratory tract via airborne droplet and spreads to the lymphatic system. Rubella Virus virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
  • Fine, pink macules on the face and neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess
  • Becomes pinpoint and spreads to the trunk and extremities
  • Less extensive than measles Measles Measles (also known as rubeola) is caused by a single-stranded, linear, negative-sense RNA virus of the family Paramyxoviridae. It is highly contagious and spreads by respiratory droplets or direct-contact transmission from an infected person. Typically a disease of childhood, measles classically starts with cough, coryza, and conjunctivitis, followed by a maculopapular rash. Measles Virus
  • Forschheimer spots ( petechiae Petechiae Primary Skin Lesions on the soft palate Palate The palate is the structure that forms the roof of the mouth and floor of the nasal cavity. This structure is divided into soft and hard palates. Palate: Anatomy)
  • Associated with fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, lymphadenopathy Lymphadenopathy Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy, and conjunctivitis Conjunctivitis Conjunctivitis is a common inflammation of the bulbar and/or palpebral conjunctiva. It can be classified into infectious (mostly viral) and noninfectious conjunctivitis, which includes allergic causes. Patients commonly present with red eyes, increased tearing, burning, foreign body sensation, and photophobia. Conjunctivitis
  • Clinical diagnosis
  • Serologic testing
Symptomatic treatment
5th disease ( erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion infectiosum)
  • Clinical diagnosis
  • IgM IgM A class of immunoglobulin bearing mu chains (immunoglobulin mu-chains). Igm can fix complement. The name comes from its high molecular weight and originally being called a macroglobulin. Immunoglobulins: Types and Functions or PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR) testing is rarely needed.
Symptomatic treatment
Scarlet fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
  • Caused by Streptococcus Streptococcus Streptococcus is one of the two medically important genera of gram-positive cocci, the other being Staphylococcus. Streptococci are identified as different species on blood agar on the basis of their hemolytic pattern and sensitivity to optochin and bacitracin. There are many pathogenic species of streptococci, including S. pyogenes, S. agalactiae, S. pneumoniae, and the viridans streptococci. Streptococcus pyogenes
  • Begins with fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever and sore throat Throat The pharynx is a component of the digestive system that lies posterior to the nasal cavity, oral cavity, and larynx. The pharynx can be divided into the oropharynx, nasopharynx, and laryngopharynx. Pharyngeal muscles play an integral role in vital processes such as breathing, swallowing, and speaking. Pharynx: Anatomy
  • Flushed cheeks Cheeks The part of the face that is below the eye and to the side of the nose and mouth. Melasma
  • Strawberry tongue Strawberry tongue Kawasaki Disease
  • Sandpaper-like rash Rash Rocky Mountain Spotted Fever on neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess, trunk, and extremities
  • Pastia’s lines
  • Clinical diagnosis
  • Rapid antigen Antigen Substances that are recognized by the immune system and induce an immune reaction. Vaccination or throat Throat The pharynx is a component of the digestive system that lies posterior to the nasal cavity, oral cavity, and larynx. The pharynx can be divided into the oropharynx, nasopharynx, and laryngopharynx. Pharyngeal muscles play an integral role in vital processes such as breathing, swallowing, and speaking. Pharynx: Anatomy culture to confirm
  • Penicillin Penicillin Rheumatic Fever
  • Amoxicillin Amoxicillin A broad-spectrum semisynthetic antibiotic similar to ampicillin except that its resistance to gastric acid permits higher serum levels with oral administration. Penicillins
Chickenpox Chickenpox A highly contagious infectious disease caused by the varicella-zoster virus. It usually affects children, is spread by direct contact or respiratory route via droplet nuclei, and is characterized by the appearance on the skin and mucous membranes of successive crops of typical pruritic vesicular lesions that are easily broken and become scabbed. Chickenpox is relatively benign in children, but may be complicated by pneumonia and encephalitis in adults. Varicella-Zoster Virus/Chickenpox
  • Caused by varicella-zoster virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
  • Rash Rash Rocky Mountain Spotted Fever appears in crops and progresses from macules to papules to vesicles Vesicles Female Genitourinary Examination on a red base
  • Lesions eventually crust Crust Dried exudate of body fluids (blood, pus, or sebum) on an area of damaged skin Secondary Skin Lesions.
  • Intense pruritis
  • Begins on trunk and spreads to the face and extremities
  • Prodrome Prodrome Symptoms that appear 24–48 hours prior to migraine onset. Migraine Headache of fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever and malaise Malaise Tick-borne Encephalitis Virus
  • Clinical diagnosis
  • Serologic testing may be done to confirm the diagnosis.
HHV: human herpesvirus
PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR): polymerase chain reaction Polymerase chain reaction Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR)

Comparison of Common Localized Rashes

Table: Summary of common localized rashes
Condition Features Diagnosis Management
Contact dermatitis Contact dermatitis A type of acute or chronic skin reaction in which sensitivity is manifested by reactivity to materials or substances coming in contact with the skin. It may involve allergic or non-allergic mechanisms. Male Genitourinary Examination
  • Clinical diagnosis
  • Patch testing
  • Avoid causative agents.
  • Topical steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors
  • Antihistamines Antihistamines Antihistamines are drugs that target histamine receptors, particularly H1 and H2 receptors. H1 antagonists are competitive and reversible inhibitors of H1 receptors. First-generation antihistamines cross the blood-brain barrier and can cause sedation. Antihistamines
  • Emollients Emollients Oleaginous substances used topically to soothe, soften or protect skin or mucous membranes. They are used also as vehicles for other dermatologic agents. Pityriasis Rosea
Tinea corporis Tinea corporis Dermatophytes/Tinea Infections Topical or oral antifungals
Seborrheic dermatitis Seborrheic dermatitis Seborrheic dermatitis is a common chronic, relapsing skin disorder that presents as erythematous plaques with greasy, yellow scales in susceptible areas (scalp, face, and trunk). Seborrheic dermatitis has a biphasic incidence, occurring in two peaks: first in infants, then in adolescence and early adulthood. Seborrheic Dermatitis
  • Clinical diagnosis
  • Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma to confirm
  • Topical antifungals
  • Topical steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors
  • Calcineurin inhibitors Calcineurin Inhibitors Compounds that inhibit or block the phosphatase activity of calcineurin. Immunosuppressants
  • Keratolytic agents
Impetigo Impetigo Impetigo is a highly contagious superficial bacterial infection typically caused by Staphylococcus aureus (most common) and Streptococcus pyogenes. Impetigo most commonly presents in children aged 2 to 5 years with lesions that evolve from papules to vesicles to pustules, which eventually break down to form characteristic “honey-colored” crusts. Impetigo
  • Mild-to-moderate cases: topical antibiotics
  • Bullous or severe cases: oral antibiotics
Cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis
  • Bacterial infection of the dermis Dermis A layer of vascularized connective tissue underneath the epidermis. The surface of the dermis contains innervated papillae. Embedded in or beneath the dermis are sweat glands; hair follicles; and sebaceous glands. Skin: Structure and Functions and subcutaneous tissues
  • Erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion and induration Induration Dermatologic Examination
  • Warm to the touch
  • Poorly demarcated
  • Clinical diagnosis
  • Blood cultures Cultures Klebsiella if sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock is present
  • Penicillins Penicillins Beta-lactam antibiotics contain a beta-lactam ring as a part of their chemical structure. Drugs in this class include penicillin G and V, penicillinase-sensitive and penicillinase-resistant penicillins, cephalosporins, carbapenems, and aztreonam. Penicillins
  • Vancomycin Vancomycin Antibacterial obtained from streptomyces orientalis. It is a glycopeptide related to ristocetin that inhibits bacterial cell wall assembly and is toxic to kidneys and the inner ear. Glycopeptides for MRSA MRSA A strain of Staphylococcus aureus that is non-susceptible to the action of methicillin. The mechanism of resistance usually involves modification of normal or the presence of acquired penicillin binding proteins. Staphylococcus
Erysipelas Erysipelas Erysipelas is a bacterial infection of the superficial layer of the skin extending to the skin’s superficial lymphatic vessels. This infection presents as a raised, well-defined, tender, and bright red rash. Typically on the legs or face, but erysipelas can occur anywhere on the skin. Erysipelas
  • A more superficial bacterial infection than cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis
  • Involves the upper dermis Dermis A layer of vascularized connective tissue underneath the epidermis. The surface of the dermis contains innervated papillae. Embedded in or beneath the dermis are sweat glands; hair follicles; and sebaceous glands. Skin: Structure and Functions and superficial lymphatics
  • Well-defined erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion with raised demarcation
  • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and tenderness
  • Clinical diagnosis
  • Blood cultures Cultures Klebsiella if sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock is present
  • Penicillins Penicillins Beta-lactam antibiotics contain a beta-lactam ring as a part of their chemical structure. Drugs in this class include penicillin G and V, penicillinase-sensitive and penicillinase-resistant penicillins, cephalosporins, carbapenems, and aztreonam. Penicillins
  • Vancomycin Vancomycin Antibacterial obtained from streptomyces orientalis. It is a glycopeptide related to ristocetin that inhibits bacterial cell wall assembly and is toxic to kidneys and the inner ear. Glycopeptides for MRSA MRSA A strain of Staphylococcus aureus that is non-susceptible to the action of methicillin. The mechanism of resistance usually involves modification of normal or the presence of acquired penicillin binding proteins. Staphylococcus
Necrotizing fasciitis Necrotizing fasciitis Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis
  • Life-threatening bacterial infection of the subcutaneous tissues and fascia Fascia Layers of connective tissue of variable thickness. The superficial fascia is found immediately below the skin; the deep fascia invests muscles, nerves, and other organs. Cellulitis
  • Rapidly progressive erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion, swelling Swelling Inflammation, and edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema
  • Severe pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
  • Bullae Bullae Erythema Multiforme and necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage
  • Systemic toxicity Toxicity Dosage Calculation
  • Clinical diagnosis
  • Blood and tissue culture
  • Imaging studies
Herpes zoster Herpes Zoster Varicella-zoster virus (VZV) is a linear, double-stranded DNA virus in the Herpesviridae family. Shingles (also known as herpes zoster) is more common in adults and occurs due to the reactivation of VZV. Varicella-Zoster Virus/Chickenpox ( shingles Shingles Varicella-zoster virus (VZV) is a linear, double-stranded DNA virus in the Herpesviridae family. Shingles (also known as herpes zoster) is more common in adults and occurs due to the reactivation of VZV. Varicella-Zoster Virus/Chickenpox)
  • Caused by reactivation Reactivation Herpes Simplex Virus 1 and 2 of the varicella-zoster virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
  • Vesicular eruption in a dermatomal Dermatomal Dermatologic Examination distribution
  • Rash Rash Rocky Mountain Spotted Fever is preceded by pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways.
  • Complicated by postherpetic neuralgia Postherpetic neuralgia Pain in nerves, frequently involving facial skin, resulting from the activation the latent varicella-zoster virus. The two forms of the condition preceding the pain are herpes zoster oticus; and herpes zoster ophthalmicus. Following the healing of the rashes and blisters, the pain sometimes persists. Herpes Zoster (Shingles)
  • Clinical diagnosis
  • PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR)
  • Tzanck smear Tzanck smear Herpes Simplex Virus 1 and 2
  • Prevented by vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination
  • Antiviral Antiviral Antivirals for Hepatitis B agents may reduce duration of symptoms.
  • Symptomatic therapy
IV: intravenous
MRSA MRSA A strain of Staphylococcus aureus that is non-susceptible to the action of methicillin. The mechanism of resistance usually involves modification of normal or the presence of acquired penicillin binding proteins. Staphylococcus: methicillin-resistant S. aureus S. aureus Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications. Staphylococcus
PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR): polymerase chain reaction Polymerase chain reaction Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR)
KOH: potassium Potassium An element in the alkali group of metals with an atomic symbol k, atomic number 19, and atomic weight 39. 10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the water-electrolyte balance. Hyperkalemia hydroxide

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