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Alopecia

Alopecia is the loss of hair in areas anywhere on the body where hair normally grows. Alopecia may be defined as scarring Scarring Inflammation or non-scarring, localized or diffuse, congenital Congenital Chorioretinitis or acquired, reversible or permanent, or confined to the scalp or universal; however, alopecia is usually classified using the 1st 3 factors. The etiologies of alopecia are usually divided into disorders in which the hair follicle Hair follicle A tube-like invagination of the epidermis from which the hair shaft develops and into which sebaceous glands open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. Follicles of very long hairs extend into the subcutaneous layer of tissue under the skin. Cowden Syndrome is abnormal or damaged and those in which the hair follicle Hair follicle A tube-like invagination of the epidermis from which the hair shaft develops and into which sebaceous glands open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. Follicles of very long hairs extend into the subcutaneous layer of tissue under the skin. Cowden Syndrome is normal but the cycling of hair growth is abnormal. The most common presentations are androgenetic hair loss, alopecia areata, traction alopecia, tinea capitis Tinea capitis Ringworm of the scalp and associated hair mainly caused by species of Microsporum; Trichophyton; and Epidermophyton, which may occasionally involve the eyebrows and eyelashes. Dermatophytes/Tinea Infections, and telogen effluvium Telogen Effluvium Dermatologic Examination. Diagnosis is made through a positive medical history and physical exam findings. Treatment depends on the type and potential for regrowth.

Last updated: 1 Feb, 2021

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Overview

Normal phases of hair growth

  1. Anagen: 
  2. Catagen: 
  3. Telogen: 
  4. After the telogen phase Telogen phase Skin: Structure and Functions, hairs fall out at a rate of 50–100 scalp hairs per day.
Stages of hair growth

The 3 stages of hair growth:
Anagen represents the periods of active growth; 90% of all hair follicles are in the anagen phase Anagen phase Skin: Structure and Functions. Catagen represents the periods of degeneration and regression Regression Corneal Abrasions, Erosion, and Ulcers of the hair follicle Hair follicle A tube-like invagination of the epidermis from which the hair shaft develops and into which sebaceous glands open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. Follicles of very long hairs extend into the subcutaneous layer of tissue under the skin. Cowden Syndrome; < 1% of all hair follicles are in the catagen phase Catagen phase Skin: Structure and Functions. Telogen represents the resting periods; < 10% of all hair follicles are in the telogen phase Telogen phase Skin: Structure and Functions. After the telogen phase Telogen phase Skin: Structure and Functions, the hair naturally falls out.

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Classification or types of alopecia

The most common classifications of hair loss are cicatricial ( scarring Scarring Inflammation) alopecia, non-scarring alopecia, and structural hair disorders.

Cicatricial ( scarring Scarring Inflammation):

The hair follicle Hair follicle A tube-like invagination of the epidermis from which the hair shaft develops and into which sebaceous glands open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. Follicles of very long hairs extend into the subcutaneous layer of tissue under the skin. Cowden Syndrome undergoes irreversible damage, which heals through fibrosis Fibrosis Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury. Bronchiolitis Obliterans, leading to a cessation in hair cycling and permanent hair loss.

  • Secondary: caused by inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation due to physical trauma or a condition that is not a primary scalp disease (includes tinea capitis Tinea capitis Ringworm of the scalp and associated hair mainly caused by species of Microsporum; Trichophyton; and Epidermophyton, which may occasionally involve the eyebrows and eyelashes. Dermatophytes/Tinea Infections, neoplasms Neoplasms New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms. Benign Bone Tumors, radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma therapy, and surgical scars)
  • Primary: caused by inflammatory disorders of the scalp in which the hair follicle Hair follicle A tube-like invagination of the epidermis from which the hair shaft develops and into which sebaceous glands open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. Follicles of very long hairs extend into the subcutaneous layer of tissue under the skin. Cowden Syndrome is the main target in destruction, resulting in permanent hair loss (divided into 3 subtypes: lymphocytic, neutrophilic, and mixed)
Table: Subtypes of primary cicatricial alopecia
Lymphocytic Neutrophilic Mixed
  • Alopecia mucinosa
  • Central centrifugal cicatricial alopecia
  • Discoid lupus erythematosus
  • Keratosis follicularis spinulosa decalvans
  • Lichen planopilaris Lichen Planopilaris Lichen Planus
  • Frontal Frontal The bone that forms the frontal aspect of the skull. Its flat part forms the forehead, articulating inferiorly with the nasal bone and the cheek bone on each side of the face. Skull: Anatomy fibrosing alopecia
  • Dissecting 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 of the scalp
  • Folliculitis decalvans
  • Acne keloidalis Acne keloidalis A type of acneiform disorder in which secondary pyogenic infection in and around pilosebaceous structures ends in keloidal scarring. It manifests as persistent folliculitis of the back of the neck associated with occlusion of the follicular orifices. It is most often encountered in black or Asian men. Hypertrophic and Keloid Scars nuchae
  • Acne necrotica
  • Erosive pustular dermatosis of the scalp

Non-scarring:

Inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation is mild or absent so that the hair follicle Hair follicle A tube-like invagination of the epidermis from which the hair shaft develops and into which sebaceous glands open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. Follicles of very long hairs extend into the subcutaneous layer of tissue under the skin. Cowden Syndrome is not damaged, resulting in non-permanent hair loss (divided into 3 subtypes: focal, patterned, and diffuse).

Table: Subtypes of non-scarring alopecia
Focal Patterned Diffuse
  • Alopecia areata
  • Alopecia syphilitica
  • Pressure-induced (postoperative) alopecia
  • Temporal triangular alopecia
  • Traction alopecia
  • Androgenetic alopecia Androgenetic Alopecia Dermatologic Examination in men (male-pattern hair loss)
  • Female-pattern hair loss
  • Trichotillomania Trichotillomania Trichotillomania (hair-pulling disorder (HPD)) is defined as repetitive pulling of one’s hair resulting in hair loss that may be visible to others. This disorder is classified under obsessive-compulsive and related disorders, as there is tension prior to the act that is relieved after the hair-pulling. Trichotillomania

Structural hair disorders:

Structural hair disorders are inherited or acquired disorders of hair structure that result in brittle or fragile hair, which lead to hair breakage or the appearance of hair growth failure Growth failure Chronic Granulomatous Disease.

Table: Structural hair disorders
Inherited Acquired
  • Menkes disease
  • Monilethrix
  • Trichothiodystrophy
  • Trichorrhexis invaginata
  • Trichorrhexis nodosa
  • Trichoptilosis

Diagnosis

Medical history:

  • It’s important to determine the duration, rate of progression, location, pattern, and extent of hair loss along with the patient’s associated symptoms, medical disorders/events, family history Family History Adult Health Maintenance of hair loss, medications, and diet/caloric intake.
  • Drugs associated with hair loss: 
    • Amantadine Amantadine An antiviral that is used in the prophylactic or symptomatic treatment of influenza A. It is also used as an antiparkinsonian agent, to treat extrapyramidal reactions, and for postherpetic neuralgia. The mechanisms of its effects in movement disorders are not well understood but probably reflect an increase in synthesis and release of dopamine, with perhaps some inhibition of dopamine uptake. Antivirals for Influenza
    • Amiodarone Amiodarone An antianginal and class III antiarrhythmic drug. It increases the duration of ventricular and atrial muscle action by inhibiting potassium channels and voltage-gated sodium channels. There is a resulting decrease in heart rate and in vascular resistance. Pulmonary Fibrosis
    • Isotretinoin
    • Anticoagulants Anticoagulants Anticoagulants are drugs that retard or interrupt the coagulation cascade. The primary classes of available anticoagulants include heparins, vitamin K-dependent antagonists (e.g., warfarin), direct thrombin inhibitors, and factor Xa inhibitors. Anticoagulants
    • Ketoconazole Ketoconazole Broad spectrum antifungal agent used for long periods at high doses, especially in immunosuppressed patients. Azoles 
    • Anticonvulsants
    • Lithium Lithium An element in the alkali metals family. It has the atomic symbol li, atomic number 3, and atomic weight [6. 938; 6. 997]. Salts of lithium are used in treating bipolar disorder. Ebstein’s Anomaly
    • Captopril Captopril A potent and specific inhibitor of peptidyl-dipeptidase a. It blocks the conversion of angiotensin I to angiotensin II, a vasoconstrictor and important regulator of arterial blood pressure. Captopril acts to suppress the renin-angiotensin system and inhibits pressure responses to exogenous angiotensin. Hypertension Drugs
    • Penicillamine Penicillamine 3-mercapto-d-valine. The most characteristic degradation product of the penicillin antibiotics. It is used as an antirheumatic and as a chelating agent in wilson’s disease. Wilson’s Disease
    • Statins Statins Statins are competitive inhibitors of HMG-CoA reductase in the liver. HMG-CoA reductase is the rate-limiting step in cholesterol synthesis. Inhibition results in lowered intrahepatocytic cholesterol formation, resulting in up-regulation of LDL receptors and, ultimately, lowering levels of serum LDL and triglycerides. Statins
    • Propranolol Propranolol A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for myocardial infarction; arrhythmia; angina pectoris; hypertension; hyperthyroidism; migraine; pheochromocytoma; and anxiety but adverse effects instigate replacement by newer drugs. Antiadrenergic Drugs
    • Cimetidine Cimetidine A histamine congener, it competitively inhibits histamine binding to histamine h2 receptors. Cimetidine has a range of pharmacological actions. It inhibits gastric acid secretion, as well as pepsin and gastrin output. Antihistamines
    • Colchicine Colchicine A major alkaloid from colchicum autumnale l. And found also in other colchicum species. Its primary therapeutic use is in the treatment of gout. Gout Drugs
  • Medical conditions associated with hair loss:
    • Major illness, surgery, and/or psychologic stress
    • Significant weight loss Weight loss Decrease in existing body weight. Bariatric Surgery 
    • Chronic iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements deficiency
    • Thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy disorders 
    • Childbirth
    • Poisoning from arsenic Arsenic A shiny gray element with atomic symbol as, atomic number 33, and atomic weight 75. It occurs throughout the universe, mostly in the form of metallic arsenides. Most forms are toxic. According to the fourth annual report on carcinogens, arsenic and certain arsenic compounds have been listed as known carcinogens. Metal Poisoning (Lead, Arsenic, Iron), mercury Mercury A silver metallic element that exists as a liquid at room temperature. It has the atomic symbol Hg (from hydrargyrum, liquid silver), atomic number 80, and atomic weight 200. 59. Mercury is used in many industrial applications and its salts have been employed therapeutically as purgatives, antisyphilitics, disinfectants, and astringents. It can be absorbed through the skin and mucous membranes which leads to mercury poisoning. Because of its toxicity, the clinical use of mercury and mercurials is diminishing. Renal Tubular Acidosis, or thallium

Physical exam:

  • Visual inspection Inspection Dermatologic Examination
    • Presence versus absence of follicular ostia (absence = scarring Scarring Inflammation alopecia)
    • Distribution and density of hair
    • Pattern of hair loss
    • Use of contrasting colored paper to fully visualize hair
    • Examine other sites of hair plus nails, 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 teeth Teeth Normally, an adult has 32 teeth: 16 maxillary and 16 mandibular. These teeth are divided into 4 quadrants with 8 teeth each. Each quadrant consists of 2 incisors (dentes incisivi), 1 canine (dens caninus), 2 premolars (dentes premolares), and 3 molars (dentes molares). Teeth are composed of enamel, dentin, and dental cement. Teeth: Anatomy
  • Trichoscopy: dermoscopy Dermoscopy A noninvasive technique that enables direct microscopic examination of the surface and architecture of the skin. Seborrheic Keratosis of the hair and scalp, which allows for better visualization 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, follicular ostia, hair shafts, scale Scale Dermatologic Examination, erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion, and blood vessels
  • Hair pull test: identifies active hair loss by grasping and slightly tugging 50–60 hair fibers, easy extraction of > 6 hair fibers suggests active hair loss

Additional tests:

  • Microscopy: microscopic evaluation of the proximal hair ends, which is useful for determining the phase of the shedding hair
  • Scalp biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma: used in scarring Scarring Inflammation forms of alopecia to distinguish inflammatory from non-inflammatory causes
  • Trichograms and phototrichograms: used to evaluate non-scarring hair loss and treatment response
  • Laboratory: 
    • Thyroid-stimulating hormone Thyroid-stimulating hormone A glycoprotein hormone secreted by the adenohypophysis. Thyrotropin stimulates thyroid gland by increasing the iodide transport, synthesis and release of thyroid hormones (thyroxine and triiodothyronine). Thyroid Hormones (TSH) to assess thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy disorders
    • Serum iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements and ferritin Ferritin Iron-containing proteins that are widely distributed in animals, plants, and microorganisms. Their major function is to store iron in a nontoxic bioavailable form. Each ferritin molecule consists of ferric iron in a hollow protein shell (apoferritins) made of 24 subunits of various sequences depending on the species and tissue types. Hereditary Hemochromatosis to assess iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements deficiency
    • Rapid plasma reagin test Rapid plasma reagin test Treponema to assess for syphilis Syphilis Syphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis

Androgenetic Alopecia

Definition

Androgenetic alopecia Androgenetic Alopecia Dermatologic Examination is a hereditary type of hair loss that is mediated by the presence of the androgen dihydrotestosterone Dihydrotestosterone A potent androgenic metabolite of testosterone. It is produced by the action of the enzyme 3-oxo-5-alpha-steroid 4-dehydrogenase. Gonadal Hormones ( DHT DHT A potent androgenic metabolite of testosterone. It is produced by the action of the enzyme 3-oxo-5-alpha-steroid 4-dehydrogenase. Gonadal Hormones) and is the most common type of alopecia.

Male-pattern hair loss

  • Epidemiology:
    • Most common alopecia in men
    • Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency increases with age.
    • Affects 80% of men by age 80
    • Lower prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency in Chinese, Asian, and African Americans than in Caucasians Caucasians Esophageal Cancer
  • Etiology:
    • Genetic predisposition (androgen-dependent trait) 
    • Related to the X chromosome Chromosome In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. Basic Terms of Genetics
  • Pathophysiology:
    1. Testosterone Testosterone A potent androgenic steroid and major product secreted by the leydig cells of the testis. Its production is stimulated by luteinizing hormone from the pituitary gland. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to dihydrotestosterone or estradiol. Androgens and Antiandrogens is converted to DHT DHT A potent androgenic metabolite of testosterone. It is produced by the action of the enzyme 3-oxo-5-alpha-steroid 4-dehydrogenase. Gonadal Hormones by 5-alpha-reductase.
    2. DHT DHT A potent androgenic metabolite of testosterone. It is produced by the action of the enzyme 3-oxo-5-alpha-steroid 4-dehydrogenase. Gonadal Hormones binds to the androgen receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors in hair follicles and activates genes Genes A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. DNA Types and Structure that shorten the anagen phase Anagen phase Skin: Structure and Functions.
    3. Leads to follicular miniaturization of hair follicles of the scalp (a progressive decrease in the ratio of terminal hairs Terminal hairs Skin: Structure and Functions to shorter, thinner vellus hairs)
  • Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor:
    • Hair loss can begin any time after puberty Puberty Puberty is a complex series of physical, psychosocial, and cognitive transitions usually experienced by adolescents (11-19 years of age). Puberty is marked by a growth in stature and the development of secondary sexual characteristics, achievement of fertility, and changes in most body systems. Puberty (usually in the late 20s) and progresses over the patient’s lifetime.
    • Receding mid-temporal hairline
    • Vertex has diffuse thinning/balding with intact frontal Frontal The bone that forms the frontal aspect of the skull. Its flat part forms the forehead, articulating inferiorly with the nasal bone and the cheek bone on each side of the face. Skull: Anatomy hair.
    • Preservation of hair density in the occipital Occipital Part of the back and base of the cranium that encloses the foramen magnum. Skull: Anatomy region
    • Visible reduction in hair density
  • Diagnosis: based on history and exam
  • Management:
    • 1st-line therapy: 
      • Oral finasteride Finasteride An orally active 3-oxo-5-alpha-steroid 4-dehydrogenase inhibitor. It is used as a surgical alternative for treatment of benign prostatic hyperplasia. Androgens and Antiandrogens: 5-alpha-reductase inhibitor that inhibits the conversion of testosterone Testosterone A potent androgenic steroid and major product secreted by the leydig cells of the testis. Its production is stimulated by luteinizing hormone from the pituitary gland. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to dihydrotestosterone or estradiol. Androgens and Antiandrogens to DHT DHT A potent androgenic metabolite of testosterone. It is produced by the action of the enzyme 3-oxo-5-alpha-steroid 4-dehydrogenase. Gonadal Hormones and inhibits follicular miniaturization
      • Topical minoxidil: vasodilator that increases the duration of anagen, shortening telogen, and enlarging miniaturized follicles
    • Other options:
      • Hair transplant surgery
      • Low-level laser light therapy
      • Cosmetic use of hairpieces
Male-pattern hair loss

Androgenetic alopecia Androgenetic Alopecia Dermatologic Examination, or male-pattern hair loss

Image: “Alopecia” by Welshsk. License: CC BY 3.0

Female-pattern hair loss

  • Epidemiology: 
    • A common condition affecting 19% of Caucasian women
    • Most commonly occurs following menopause Menopause Menopause is a physiologic process in women characterized by the permanent cessation of menstruation that occurs after the loss of ovarian activity. Menopause can only be diagnosed retrospectively, after 12 months without menstrual bleeding. Menopause
    • Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency increases with age, with ⅓ of women being affected by age 70.
  • Etiology
    • Not well understood
    • Androgen excess may play a role.
    • Genetic predisposition is suspected.
  • Pathophysiology:
    • Transformation Transformation Change brought about to an organism’s genetic composition by unidirectional transfer (transfection; transduction, genetic; conjugation, genetic, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell’s genome. Bacteriology of the terminal hair follicle Hair follicle A tube-like invagination of the epidermis from which the hair shaft develops and into which sebaceous glands open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. Follicles of very long hairs extend into the subcutaneous layer of tissue under the skin. Cowden Syndrome to a thinner vellus hair Vellus hair Skin: Structure and Functions follicle via follicular miniaturization
    • Shortened anagen phase Anagen phase Skin: Structure and Functions and lengthened telogen phase Telogen phase Skin: Structure and Functions
  • Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor:
    • Diffuse thinning of hair
    • Frontal Frontal The bone that forms the frontal aspect of the skull. Its flat part forms the forehead, articulating inferiorly with the nasal bone and the cheek bone on each side of the face. Skull: Anatomy hairline is thinned yet preserved.
    • Progressively widening midline part leading to crown thinning
    • Preservation of hair density in the occipital Occipital Part of the back and base of the cranium that encloses the foramen magnum. Skull: Anatomy region
  • Diagnosis: 
    • Based on history and exam
    • Laboratory: Free and total testosterone Testosterone A potent androgenic steroid and major product secreted by the leydig cells of the testis. Its production is stimulated by luteinizing hormone from the pituitary gland. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to dihydrotestosterone or estradiol. Androgens and Antiandrogens level and dehydroepiandrosterone Dehydroepiandrosterone A major C19 steroid produced by the adrenal cortex. It is also produced in small quantities in the testis and the ovary. Dehydroepiandrosterone (DHEA) can be converted to testosterone; androstenedione; estradiol; and estrone. Androgens and Antiandrogens sulfate (DHEAS) level can test for an underlying hyperandrogenic state.
  • Management:
    • 1st-line therapy: topical minoxidil (vasodilator that increases the duration of anagen, shortening telogen, and enlarging miniaturized follicles)
    • 2nd-line therapies: 
      • Spironolactone Spironolactone A potassium sparing diuretic that acts by antagonism of aldosterone in the distal renal tubules. It is used mainly in the treatment of refractory edema in patients with congestive heart failure, nephrotic syndrome, or hepatic cirrhosis. Its effects on the endocrine system are utilized in the treatments of hirsutism and acne but they can lead to adverse effects. Potassium-sparing Diuretics: aldosterone Aldosterone A hormone secreted by the adrenal cortex that regulates electrolyte and water balance by increasing the renal retention of sodium and the excretion of potassium. Hyperkalemia antagonist that competitively blocks androgen receptors Receptors Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors and inhibits androgen synthesis Synthesis Polymerase Chain Reaction (PCR)
      • Finasteride Finasteride An orally active 3-oxo-5-alpha-steroid 4-dehydrogenase inhibitor. It is used as a surgical alternative for treatment of benign prostatic hyperplasia. Androgens and Antiandrogens: 5-alpha-reductase inhibitor that inhibits the conversion of testosterone Testosterone A potent androgenic steroid and major product secreted by the leydig cells of the testis. Its production is stimulated by luteinizing hormone from the pituitary gland. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to dihydrotestosterone or estradiol. Androgens and Antiandrogens to DHT DHT A potent androgenic metabolite of testosterone. It is produced by the action of the enzyme 3-oxo-5-alpha-steroid 4-dehydrogenase. Gonadal Hormones and inhibits follicular miniaturization
    • Other options:
      • The use of wigs or cosmetic camouflaging
      • Hair transplant surgery

Alopecia Areata

Definition

Alopecia areata is a chronic, relapsing, autoimmune disorder Autoimmune Disorder Septic Arthritis in which the body’s immune system Immune system The body’s defense mechanism against foreign organisms or substances and deviant native cells. It includes the humoral immune response and the cell-mediated response and consists of a complex of interrelated cellular, molecular, and genetic components. Primary Lymphatic Organs targets anagen hair follicles and causes non-scarring hair loss.

Epidemiology

  • Occurs in 1% of the population
  • The lifetime risk is approximately 2%.
  • Occurs at similar rates in males and females
  • The average age of onset is approximately 30 years.

Etiology

  • Autoimmune disease, where hair follicles are targeted and transition prematurely from the anagen growth phase Growth phase Skin: Structure and Functions to the catagen and telogen phases
  • Genetic predisposition also plays a role.
  • Associated disorders:
    • Other autoimmune diseases Autoimmune diseases Disorders that are characterized by the production of antibodies that react with host tissues or immune effector cells that are autoreactive to endogenous peptides. Selective IgA Deficiency: vitiligo Vitiligo Vitiligo is the most common depigmenting disorder and is caused by the destruction of melanocytes. Patients present with hypo- or depigmented macules or patches which often occur on the face, hands, knees, and/or genitalia. Vitiligo, lupus, 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, scleroderma Scleroderma Scleroderma (systemic sclerosis) is an autoimmune condition characterized by diffuse collagen deposition and fibrosis. The clinical presentation varies from limited skin involvement to diffuse involvement of internal organs. Scleroderma, thyroiditis Thyroiditis Thyroiditis is a catchall term used to describe a variety of conditions that have inflammation of the thyroid gland in common. It includes pathologies that cause an acute illness with severe thyroid pain (e.g., subacute thyroiditis and infectious thyroiditis) as well as conditions in which there is no clinically evident inflammation and the manifestations primarily reflect thyroid dysfunction or a goiter (e.g., painless thyroiditis and fibrous Riedel’s thyroiditis). Thyroiditis, celiac disease Celiac disease Celiac disease (also known as celiac sprue or gluten enteropathy) is an autoimmune reaction to gliadin, which is a component of gluten. Celiac disease is closely associated with HLA-DQ2 and HLA-DQ8. The immune response is localized to the proximal small intestine and causes the characteristic histologic findings of villous atrophy, crypt hyperplasia, and intraepithelial lymphocytosis. Celiac Disease, 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), allergic rhinitis Rhinitis Inflammation of the nasal mucosa, the mucous membrane lining the nasal cavities. Rhinitis
    • Genetic disorders: Down’s syndrome
    • Psychosocial disorders: stress, anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder, mood disorders

Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor

  • Sudden onset of hair loss over a few weeks that may relapse Relapse Relapsing Fever throughout the patient’s life
  • Usually asymptomatic and not associated with pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, but occasionally may present with pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema) or burning that precedes the loss of hair
  • Hair loss occurs in well-demarcated, smooth, circular patches Patches Vitiligo.
  • Commonly affects the scalp, but may also affect Affect The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves. Psychiatric Assessment the eyebrows, eyelashes, and beard 
  • Exclamation point hairs: short, broken hairs where the proximal end is narrower than the distal end
  • Nail abnormalities: pitting, fissuring, red spots, or separation from the nail bed Nail bed Skin: Structure and Functions
  • Types/patterns of distribution:
    • Areata: patchy areas of hair loss
    • Ophiasis: hair loss localized to the back and sides of the scalp
    • Sisaipho: sparing of the sides and back of the scalp
    • Extensive: affects > 50% of scalp
    • Totalis: total loss of scalp hair
    • Universalis: complete loss of all body hair

Diagnosis

  • Exam: smooth, round, or patchy areas of non-scarring hair loss with exclamation point hairs (pathognomonic for the areata type of alopecia)
  • Hair pull test: confirms active hair loss when > 6 hairs are easily extracted when 50–60 are pulled

Management

  • ½ of the patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will experience spontaneous regrowth of hair in less than a year.
  • 1st-line therapy:
  • 2nd-line therapy: topical anthralin (an irritant agent used as an adjunct with 1st-line therapies)
  • Refractory disease:
    • Azathioprine Azathioprine An immunosuppressive agent used in combination with cyclophosphamide and hydroxychloroquine in the treatment of rheumatoid arthritis. According to the fourth annual report on carcinogens, this substance has been listed as a known carcinogen. Immunosuppressants
    • Janus kinase inhibitors
    • Methotrexate Methotrexate An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of tetrahydrofolate dehydrogenase and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA. Antimetabolite Chemotherapy
    • Sulfasalazine Sulfasalazine A drug that is used in the management of inflammatory bowel diseases. Its activity is generally considered to lie in its metabolic breakdown product, 5-aminosalicylic acid released in the colon. Sulfonamides and Trimethoprim

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

  • Mild cases: 80% spontaneously resolve.
  • Severe cases: remain chronic or relapse Relapse Relapsing Fever after treatment

Traction Alopecia

Definition

Traction alopecia is a type of non-scarring hair loss caused by repetitive or prolonged tension on the hair.

Epidemiology

  • Higher prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency in women than men due to traction hairstyles
  • Most commonly associated with African American women with Afro-textured hair due to types of hairstyling

Etiology

  • Long-term traction associated with any hairstyle that causes tension at the follicle (e.g., weaves, braids, tight buns, and/or ponytails) or tight headgear (e.g., caps, hats)
  • Can be more severe in chemically treated hair

Pathophysiology

  • Traction on hair → perifollicular inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation → follicular miniaturization
  • Initially, traction alopecia is non-scarring but persistent traction leads to scarring Scarring Inflammation and irreversible damage.
  • High levels of interleukin (IL) 1-alpha in the scalp sebum Sebum The oily substance secreted by sebaceous glands. It is composed of keratin, fat, and cellular debris. Infectious Folliculitis support the inflammatory theory.

Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor

  • Early stages: 
    • Absent/limited hair loss with slightly decreased hair density
    • Traction folliculitis presenting as perifollicular erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion and pustules on the scalp
  • Late stages: 
    • Decreased hair density → completely hair-free patches Patches Vitiligo
    • Fringe sign: fine, residual hair retained at the margin of the anterior hairline with hair loss posteriorly
    • Hair casts: white scaling (firm cylinders ensheathing the hair shaft) that can be easily dislodged
Fringe sign and traction alopecia

Traction alopecia in an African American woman due to traction hairstyles

Image: “Figure 6” by Xu, Liu and Senna Senna Laxatives. License: CC BY 4.0

Diagnosis and management

  • Diagnosis is based on clinical evaluation.
  • Management of early stages:
    • Cessation of traction hairstyles
    • Topical minoxidil to aid in hair regrowth
    • Local corticosteroids Corticosteroids Chorioretinitis if signs of inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation are present
    • Oral tetracycline Tetracycline A naphthacene antibiotic that inhibits amino Acyl tRNA binding during protein synthesis. Drug-induced Liver Injury is also used for its anti-inflammatory effects.
  • Management of late stages:
    • Topical minoxidil to attempt hair regrowth, although regrowth is unlikely if the inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation has already led to scarring Scarring Inflammation
    • Hair transplant surgery
    • Cosmetic camouflage

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

  • Early stages: spontaneous regrowth within 3 months
  • Late stages: usually presents with scarring Scarring Inflammation and may have permanent hair loss

Tinea Capitisrelated Alopecia

Definition

Tinea capitis Tinea capitis Ringworm of the scalp and associated hair mainly caused by species of Microsporum; Trichophyton; and Epidermophyton, which may occasionally involve the eyebrows and eyelashes. Dermatophytes/Tinea Infections is a fungal infection of the scalp typically presenting as pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema) and scaling, leading to secondary cicatricial ( scarring Scarring Inflammation) alopecia.

Epidemiology

  • Common in children
  • More common in African American children

Etiology

  • 3 forms of dermatophyte infection:
    1. Endothrix: 
      • Fungal spores Spores The reproductive elements of lower organisms, such as bacteria; fungi; and cryptogamic plants. Anthrax are within the hair shaft.
      • Caused by Trichophyton Trichophyton A mitosporic fungal genus and an anamorphic form of arthroderma. Various species attack the skin, nails, and hair. Dermatophytes/Tinea Infections tonsurans
      • Presents as patches Patches Vitiligo of hair loss with black dots (distal ends of hairs that break at the scalp)
    2. Ectothrix: 
      • Fungal spores Spores The reproductive elements of lower organisms, such as bacteria; fungi; and cryptogamic plants. Anthrax surround the outside of the hair shaft.
      • Caused by Microsporum Microsporum A mitosporic oxygenales fungal genus causing various diseases of the skin and hair. The species microsporum canis produces tinea capitis and tinea corporis, which usually are acquired from domestic cats and dogs. Teleomorphs includes arthroderma (nannizzia). Dermatophytes/Tinea Infections canis
      • Presents as scaly patches Patches Vitiligo of hair loss that enlarge centrifugally over time and have associated erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion
    3. Favus: 
      • Fungal hyphae Hyphae Microscopic threadlike filaments in fungi that are filled with a layer of protoplasm. Collectively, the hyphae make up the mycelium. Mycology and air spaces are found within hair shafts.
      • Caused by Trichophyton Trichophyton A mitosporic fungal genus and an anamorphic form of arthroderma. Various species attack the skin, nails, and hair. Dermatophytes/Tinea Infections schoenleinii
      • Presents as severe hair loss with yellow cup-shaped crusts on the scalp called scutula, which surround the infected hair follicles 
  • Spread through person-to-person contact, animal vectors, and fomites Fomites Inanimate objects that carry pathogenic microorganisms and thus can serve as the source of infection. Microorganisms typically survive on fomites for minutes or hours. Common fomites include clothing, tissue paper, hairbrushes, and cooking and eating utensils. Adenovirus (e.g., combs, brushes, pillowcases, or hats)

Pathophysiology

  1. Dermatophytes Dermatophytes Tinea infections are a group of diseases caused by fungi infecting keratinized tissue (hair, nails, and skin). These infections are termed dermatomycoses and are caused by the dermatophyte fungi. There are approximately 40 dermatophyte fungi that are part of 3 genera, including Trichophyton, Epidermophyton, and Microsporum. These infections can affect any part of the body but occur most often in warm, moist regions like the groin and the feet. Dermatophytes/Tinea Infections come in contact with the stratum corneum Stratum corneum Skin: Structure and Functions of the scalp.
  2. Glycoproteins Glycoproteins Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins. Basics of Carbohydrates and keratinases produced by the fungus enable dermatophytes Dermatophytes Tinea infections are a group of diseases caused by fungi infecting keratinized tissue (hair, nails, and skin). These infections are termed dermatomycoses and are caused by the dermatophyte fungi. There are approximately 40 dermatophyte fungi that are part of 3 genera, including Trichophyton, Epidermophyton, and Microsporum. These infections can affect any part of the body but occur most often in warm, moist regions like the groin and the feet. Dermatophytes/Tinea Infections to invade 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 and hair, breaking down the keratin Keratin A class of fibrous proteins or scleroproteins that represents the principal constituent of epidermis; hair; nails; horny tissues, and the organic matrix of tooth enamel. Two major conformational groups have been characterized, alpha-keratin, whose peptide backbone forms a coiled-coil alpha helical structure consisting of type I keratin and a type II keratin, and beta-keratin, whose backbone forms a zigzag or pleated sheet structure. Alpha-keratins have been classified into at least 20 subtypes. In addition multiple isoforms of subtypes have been found which may be due to gene duplication. Seborrheic Keratosis.
  3. Infection spreads into 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 and down the hair follicle Hair follicle A tube-like invagination of the epidermis from which the hair shaft develops and into which sebaceous glands open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. Follicles of very long hairs extend into the subcutaneous layer of tissue under the skin. Cowden Syndrome.

Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor

  • Usually presents as pruritic scaly patches Patches Vitiligo with alopecia and/or broken hair shaft (black dots) 
  • May develop postauricular 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
  • Kerion: 
    • Severe form due to an intense inflammatory immune response
    • Inflammatory plaques with pustules, thick crusting, and/or pus drainage develop.
    • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and tenderness are present.
  • Favus:
    • Erythematous follicles progress to cup-shaped yellow crusts that coalesce to form adherent masses.
    • Severe, extensive alopecia develops.
    • Associated with an unpleasant odor

Diagnosis

  • Physical exam: 
    • Patches Patches Vitiligo with hair loss, scaling, or black dots on a child
    • Wood’s light shows the presence of spores Spores The reproductive elements of lower organisms, such as bacteria; fungi; and cryptogamic plants. Anthrax.
  • Dermoscopy Dermoscopy A noninvasive technique that enables direct microscopic examination of the surface and architecture of the skin. Seborrheic Keratosis
    • C-shaped/corkscrew hairs
    • Black dots with Trichophyton Trichophyton A mitosporic fungal genus and an anamorphic form of arthroderma. Various species attack the skin, nails, and hair. Dermatophytes/Tinea Infections tonsurans infection
    • Yellow scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions 
  • 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 (KOH) preparation shows the presence of branching hyphae Hyphae Microscopic threadlike filaments in fungi that are filled with a layer of protoplasm. Collectively, the hyphae make up the mycelium. Mycology.
  • Fungal cultures Cultures Klebsiella are used to confirm cases with high suspicion but a negative KOH preparation KOH preparation Primary Skin Lesions.

Management

  • 1st-line therapy is systemic antifungals: 
    • Oral griseofulvin Griseofulvin In addition to the 3 other major classes of antifungal agents (azoles, polyenes, and echinocandins), several other clinically important antifungal agents are used, including flucytosine, griseofulvin, and terbinafine. Griseofulvin acts within the stratum corneum of the skin and are used to treat dermatophyte infections of the skin, hair, and nails. Flucytosine, Griseofulvin, and Terbinafine
    • Oral terbinafine Terbinafine In addition to the 3 other major classes of antifungal agents (azoles, polyenes, and echinocandins), several other clinically important antifungal agents are used, including flucytosine, griseofulvin, and terbinafine. Terbinafine acts within the stratum corneum of the skin and are used to treat dermatophyte infections of the skin, hair, and nails. Flucytosine, Griseofulvin, and Terbinafine
  • Alternatives:
    • Oral fluconazole Fluconazole Triazole antifungal agent that is used to treat oropharyngeal candidiasis and cryptococcal meningitis in aids. Azoles
    • Oral itraconazole Itraconazole A triazole antifungal agent that inhibits cytochrome p-450-dependent enzymes required for ergosterol synthesis. Azoles 
  • Adjunctives:
    • Shampoo with antifungal Antifungal Azoles properties
    • Care not to spread to others, management for the family if the spread has already occurred

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

  • Hair regrowth usually occurs after treatment.
  • If scarring Scarring Inflammation is present, the patient may have permanent damage, which is particularly likely in kerion and favus 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.

Telogen Effluvium

Definition

Telogen effluvium Telogen Effluvium Dermatologic Examination is defined as the premature Premature Childbirth before 37 weeks of pregnancy (259 days from the first day of the mother’s last menstrual period, or 245 days after fertilization). Necrotizing Enterocolitis transition of hair follicles into the resting state (telogen) after a physiologic or psychologic stressor, which leads to diffuse, non-scarring alopecia.

Epidemiology

  • No predilection for any race or ethnic group
  • Women are more commonly affected than men.

Etiology

  • Psychosocial stressor (e.g., death of a family member, loss of a job)
  • Extreme weight loss Weight loss Decrease in existing body weight. Bariatric Surgery
  • Severe acute illness
  • General anesthesia Anesthesia A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures. Anesthesiology: History and Basic Concepts
  • Childbirth
  • Hypo- and hyperthyroidism Hyperthyroidism Hypersecretion of thyroid hormones from the thyroid gland. Elevated levels of thyroid hormones increase basal metabolic rate. Thyrotoxicosis and Hyperthyroidism
  • Iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements deficiency
  • Beginning or discontinuing hormonal contraceptive 
  • Medications (e.g., lithium Lithium An element in the alkali metals family. It has the atomic symbol li, atomic number 3, and atomic weight [6. 938; 6. 997]. Salts of lithium are used in treating bipolar disorder. Ebstein’s Anomaly, valproate Valproate A fatty acid with anticonvulsant and anti-manic properties that is used in the treatment of epilepsy and bipolar disorder. The mechanisms of its therapeutic actions are not well understood. It may act by increasing gamma-aminobutyric acid levels in the brain or by altering the properties of voltage-gated sodium channels. First-Generation Anticonvulsant Drugs, fluoxetine Fluoxetine The first highly specific serotonin uptake inhibitor. It is used as an antidepressant and often has a more acceptable side-effects profile than traditional antidepressants. Serotonin Reuptake Inhibitors and Similar Antidepressants, heparin, beta blockers, angiotensin-converting enzyme (ACE) inhibitors, 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, antituberculosis medications, antiretrovirals, androgens Androgens Androgens are naturally occurring steroid hormones responsible for development and maintenance of the male sex characteristics, including penile, scrotal, and clitoral growth, development of sexual hair, deepening of the voice, and musculoskeletal growth. Androgens and Antiandrogens)

Pathophysiology

  • Not completely understood
  • Underlying etiology/stressor → insult to the anagen bulb → follicular cycling changes, such as immediate and/or delayed anagen release Release Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane. Virology

Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor

  • Diffuse reduction of scalp hair density that may be most noticeable in bitemporal, frontal Frontal The bone that forms the frontal aspect of the skull. Its flat part forms the forehead, articulating inferiorly with the nasal bone and the cheek bone on each side of the face. Skull: Anatomy, and vertex areas
  • The daily loss of hair increases to 100–300 hair strands.
  • Acute:
  • Chronic:
Female pattern hair loss

Chronic telogen effluvium Telogen Effluvium Dermatologic Examination:
Note typical temporal recession. The hair density is otherwise normal.

Image: “CTE” by Department of Dermatology and Cutaneous Surgery, University of Miami, Miami, USA. License: CC BY 3.0

Diagnosis

Management

  • 1st-line therapy: 
    • Removal or treatment of any reversible causes
    • Cosmetic measures
    • Psychologic support
  • Adjunctive therapy:
    • Topical minoxidil: promotes hair growth
    • Iron supplementation Iron Supplementation Iron Deficiency Anemia for possible iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements deficiency anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

  • Acute cases: spontaneous regrowth usually within 6 months 
  • Chronic cases: persistent hair loss for > 6 months

Differential Diagnosis

The following are other conditions that can cause alopecia:

  • Trichotillomania Trichotillomania Trichotillomania (hair-pulling disorder (HPD)) is defined as repetitive pulling of one’s hair resulting in hair loss that may be visible to others. This disorder is classified under obsessive-compulsive and related disorders, as there is tension prior to the act that is relieved after the hair-pulling. Trichotillomania: a type of patterned, non-scarring alopecia due to deliberate hair pulling, plucking, or twisting to relieve stress or anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder. Most common in young females with family or psychosocial stress. Characterized by a wide variation in lengths of the remaining hair. Trichotillomania Trichotillomania Trichotillomania (hair-pulling disorder (HPD)) is defined as repetitive pulling of one’s hair resulting in hair loss that may be visible to others. This disorder is classified under obsessive-compulsive and related disorders, as there is tension prior to the act that is relieved after the hair-pulling. Trichotillomania usually affects the scalp, eyebrows, and eyelashes.
  • Nevus Nevus Nevi (singular nevus), also known as “moles,” are benign neoplasms of the skin. Nevus is a non-specific medical term because it encompasses both congenital and acquired lesions, hyper- and hypopigmented lesions, and raised or flat lesions. Nevus/Nevi sebaceous: a sporadic Sporadic Selective IgA Deficiency, congenital Congenital Chorioretinitis, hairless plaque Plaque Primary Skin Lesions on the face or scalp due to benign Benign Fibroadenoma growth of excess sebaceous glands resulting in loss of hair follicles in that area. Plaque Plaque Primary Skin Lesions is usually single, circular, linear, or irregular in shape. Surgical intervention may be necessary due to slight malignant potential.
  • Secondary syphilis Secondary Syphilis Syphilis: a sexually transmitted infectious Infectious Febrile Infant disease caused by the bacterium Treponema Treponema Treponema is a gram-negative, microaerophilic spirochete. Owing to its very thin structure, it is not easily seen on Gram stain, but can be visualized using dark-field microscopy. This spirochete contains endoflagella, which allow for a characteristic corkscrew movement. Treponema pallidum. If left untreated, primary syphilis Primary Syphilis Syphilis becomes secondary syphilis Secondary Syphilis Syphilis approximately 4–10 weeks after the primary infection Primary infection Herpes Simplex Virus 1 and 2. Symptoms include 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, malaise Malaise Tick-borne Encephalitis Virus, 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, moth-eaten patchy alopecia, confusion, condyloma Condyloma Sexually transmitted form of anogenital warty growth caused by the human papillomaviruses. Male Genitourinary Examination lata, and a generalized papulosquamous eruption on palms and soles.
  • 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: a common chronic papulosquamous dermatosis with distinct infantile and adult forms. Presents as erythematous, well-demarcated plaques with greasy yellow scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions in areas with hair and oily 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, such as the scalp, face, chest, and back. 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 prevents hair growth in the affected area.

References

  1. Thiedke C. C. (2003). Alopecia in women. American family physician, 67(5), 1007–1014. Retrieved on January 18th, 2020, from https://www.aafp.org/afp/2003/0301/p1007.html
  2. Levinbook, W.S. (2020). Alopecia (Hair Loss; Baldness). MSD Manuals. https://www.msdmanuals.com/professional/dermatologic-disorders/hair-disorders/alopecia?query=alopecia
  3. Adil A, Godwin M. The effectiveness of treatments for androgenetic alopecia: A systematic review and meta-analysis. J Am Acad Dermatol. 2017;77(1):136-141.e5. doi:10.1016/j.jaad.2017.02.054
  4. Messenger, A.G. (2019). Alopecia areata: Clinical manifestations and diagnosis. UpToDate. Retrieved January 18, 2021, from
    https://www.uptodate.com/contents/alopecia-areata-clinical-manifestations-and-diagnosis
  5. McMichael, A. (2020). Female pattern hair loss (androgenetic alopecia in women): Pathogenesis, clinical features, and diagnosis. UpToDate. Retrieved Jan 18, 2021, from https://www.uptodate.com/contents/female-pattern-hair-loss-androgenetic-alopecia-in-women-pathogenesis-clinical-features-and-diagnosis
  6. Khumalo, N.P. (2020.) Traction alopecia. UpToDate. Retrieved January 18, 2021, from https://www.uptodate.com/contents/traction-alopecia

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