Rhinitis

Pathophysiology

Infectious Infectious Febrile Infant rhinitis

• 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 typically use intercellular adhesion Adhesion The process whereby platelets adhere to something other than platelets, e.g., collagen; basement membrane; microfibrils; or other ‘foreign’ surfaces. Coagulation Studies molecule-1 host 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 to enter into nasal epithelial cells. 
• Signaling within cells occurs via NF NF 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-kB leading to the elaboration of pro-inflammatory cytokines Cytokines Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner. Adaptive Immune Response, which leads to:
  • Plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products exudation from submucosal capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries: Histology
  • Recruitment Recruitment Skeletal Muscle Contraction of polymorphonuclear cells to nasal epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology via interleukin-8
• Local production of cytokines Cytokines Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner. Adaptive Immune Response and kinins results in the classic symptoms of infectious Infectious Febrile Infant rhinitis/the common cold Common cold A catarrhal disorder of the upper respiratory tract, which may be viral or a mixed infection. It generally involves a runny nose, nasal congestion, and sneezing. Rhinovirus.

Allergic rhinitis

Type I hypersensitivity reaction Type I hypersensitivity reaction Type I hypersensitivity reaction is an abnormal immune response triggered by exposure to specific antigens known as allergens. In this type of hypersensitivity reaction, the presentation of the antigen to the T-helper cells (Th cells) initiates a cascade of immunologic events leading to the production of antigen-specific IgE antibodies. Type I Hypersensitivity Reaction triggers Triggers Hereditary Angioedema (C1 Esterase Inhibitor Deficiency) 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 in the nose Nose The nose is the human body’s primary organ of smell and functions as part of the upper respiratory system. The nose may be best known for inhaling oxygen and exhaling carbon dioxide, but it also contributes to other important functions, such as tasting. The anatomy of the nose can be divided into the external nose and the nasal cavity. Nose and Nasal Cavity: Anatomy, which is immunoglobulin E ( IgE IgE An immunoglobulin associated with mast cells. Overexpression has been associated with allergic hypersensitivity. Immunoglobulins: Types and Functions)-mediated.

• After initial exposure Exposure ABCDE Assessment to an allergen in atopic individuals, IgE IgE An immunoglobulin associated with mast cells. Overexpression has been associated with allergic hypersensitivity. Immunoglobulins: Types and Functions antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions bind BIND Hyperbilirubinemia of the Newborn to IgE IgE An immunoglobulin associated with mast cells. Overexpression has been associated with allergic hypersensitivity. Immunoglobulins: Types and Functions 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 on mast cells Mast cells Granulated cells that are found in almost all tissues, most abundantly in the skin and the gastrointestinal tract. Like the basophils, mast cells contain large amounts of histamine and heparin. Unlike basophils, mast cells normally remain in the tissues and do not circulate in the blood. Mast cells, derived from the bone marrow stem cells, are regulated by the stem cell factor. Innate Immunity: Phagocytes and Antigen Presentation throughout the respiratory mucosa and to basophils Basophils Granular leukocytes characterized by a relatively pale-staining, lobate nucleus and cytoplasm containing coarse dark-staining granules of variable size and stainable by basic dyes. Innate Immunity: Phagocytes and Antigen Presentation in the peripheral blood.
• B cells B cells Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation. B cells: Types and Functions then differentiate into plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products cells and produce IgE IgE An immunoglobulin associated with mast cells. Overexpression has been associated with allergic hypersensitivity. Immunoglobulins: Types and Functions antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions specific to the antigen Antigen Substances that are recognized by the immune system and induce an immune reaction. Vaccination.
• When the same allergen is inhaled, IgE IgE An immunoglobulin associated with mast cells. Overexpression has been associated with allergic hypersensitivity. Immunoglobulins: Types and Functions antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions are bridged by the allergen’s antigen Antigen Substances that are recognized by the immune system and induce an immune reaction. Vaccination.
• Mast cells Mast cells Granulated cells that are found in almost all tissues, most abundantly in the skin and the gastrointestinal tract. Like the basophils, mast cells contain large amounts of histamine and heparin. Unlike basophils, mast cells normally remain in the tissues and do not circulate in the blood. Mast cells, derived from the bone marrow stem cells, are regulated by the stem cell factor. Innate Immunity: Phagocytes and Antigen Presentation and basophils Basophils Granular leukocytes characterized by a relatively pale-staining, lobate nucleus and cytoplasm containing coarse dark-staining granules of variable size and stainable by basic dyes. Innate Immunity: Phagocytes and Antigen Presentation are activated → 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 of histamine, leukotrienes Leukotrienes A family of biologically active compounds derived from arachidonic acid by oxidative metabolism through the 5-lipoxygenase pathway. They participate in host defense reactions and pathophysiological conditions such as immediate hypersensitivity and inflammation. They have potent actions on many essential organs and systems, including the cardiovascular, pulmonary, and central nervous system as well as the gastrointestinal tract and the immune system. Eicosanoids, and kinins + inflammatory infiltrates with eosinophils Eosinophils Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin. Innate Immunity: Phagocytes and Antigen Presentation → sneezing Sneezing The sudden, forceful, involuntary expulsion of air from the nose and mouth caused by irritation to the mucous membranes of the upper respiratory tract. Rhinovirus, rhinorrhea Rhinorrhea Excess nasal drainage. Respiratory Syncytial Virus, and congestion (symptoms of allergic rhinitis)

Non-allergic rhinitis

• No single unifying pathogenesis theory
• Hormonal or autonomic stimuli produce a decrease in sympathetic activity and/or an increase in parasympathetic activity.
  • Sympathetic stimulation causes vasoconstriction Vasoconstriction The physiological narrowing of blood vessels by contraction of the vascular smooth muscle. Vascular Resistance, Flow, and Mean Arterial Pressure of the nasal blood vessels (so decreased activity causes reduced vasoconstriction Vasoconstriction The physiological narrowing of blood vessels by contraction of the vascular smooth muscle. Vascular Resistance, Flow, and Mean Arterial Pressure when needed).
  • Parasympathetic stimulation causes vasodilatation of the nasal blood vessels and increased mucous secretions (so increased activity causes an over-response).
• Other abnormal responses to neurogenic stimuli include increased concentrations of vasoactive intestinal peptide Vasoactive intestinal peptide A highly basic, 28 amino acid neuropeptide released from intestinal mucosa. It has a wide range of biological actions affecting the cardiovascular, gastrointestinal, and respiratory systems and is neuroprotective. It binds special receptors. Gastrointestinal Neural and Hormonal Signaling (potent vasodilator) and substance P ( pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways reception).
• Subtypes:
  • Rhinitis medicamentosa: rebound phenomenon after excessive use of decongestant nasal drops, usually seen after 3 consecutive days of use
  • Drug-induced rhinitis: caused by antihypertensives Antihypertensives The 1st-line medication classes for hypertension include thiazide-like diuretics, angiotensin-converting enzyme inhibitors (ACEis), angiotensin II receptor blockers (ARBs), and calcium channel blockers (CCBS). Contraindications, adverse effects, and drug-to-drug interactions are agent specific. Hypertension Drugs and NSAIDs NSAIDS Primary vs Secondary Headaches
  • Pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care rhinitis: persistent 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 of the nasal mucosa Nasal mucosa The mucous lining of the nasal cavity, including lining of the nostril (vestibule) and the olfactory mucosa. Nasal mucosa consists of ciliated cells, goblet cells, brush cells, small granule cells, basal cells (stem cells) and glands containing both mucous and serous cells. Nose and Nasal Cavity: Anatomy and even airway Airway ABCDE Assessment obstruction may be caused by hormonal changes during pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care.
  • Honeymoon rhinitis: occurs following intense sexual excitement
  • Gustatory rhinitis: associated with spicy food and/or alcohol, which stimulates the palatine sensory Sensory Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology 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 produces a cholinergic response
  • Non-air flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure rhinitis: associated with choanal atresia Atresia Hypoplastic Left Heart Syndrome (HLHS) and tracheostomy Tracheostomy Surgical formation of an opening into the trachea through the neck, or the opening so created. Laryngomalacia and Tracheomalacia

Management

Infectious Infectious Febrile Infant rhinitis

• The mainstay of treatment is symptomatic and supportive, as most cases of infectious Infectious Febrile Infant rhinitis are of viral etiology, which is self-limiting Self-Limiting Meningitis in Children and resolves spontaneously and steadily within a few days.
• Some patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may require antibiotics for laboratory-documented bacterial infection.
  • Treat rhinitis due to group A beta-hemolytic streptococci with PO penicillin Penicillin Rheumatic Fever or 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 for 10 days (cephalexin if penicillin Penicillin Rheumatic Fever is known to cause rash Rash Rocky Mountain Spotted Fever; clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides or macrolide if penicillin Penicillin Rheumatic Fever is known to cause anaphylaxis Anaphylaxis An acute hypersensitivity reaction due to exposure to a previously encountered antigen. The reaction may include rapidly progressing urticaria, respiratory distress, vascular collapse, systemic shock, and death. Type I Hypersensitivity Reaction).
  • Timely treatment is crucial for the prevention of acute rheumatic 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.
• Other underlying causes of rhinitis need to be identified and treated (e.g., retroviral therapy for HIV HIV Anti-HIV Drugs, penicillin Penicillin Rheumatic Fever for group A streptococcus Group A Streptococcus A species of gram-positive, coccoid bacteria isolated from skin lesions, blood, inflammatory exudates, and the upper respiratory tract of humans. It is a group a hemolytic Streptococcus that can cause scarlet fever and rheumatic fever. Postinfectious Glomerulonephritis, nystatin Nystatin Macrolide antifungal antibiotic complex produced by streptomyces noursei, s. Aureus, and other streptomyces species. The biologically active components of the complex are nystatin a1, a2, and a3. Polyenes for candida Candida Candida is a genus of dimorphic, opportunistic fungi. Candida albicans is part of the normal human flora and is the most common cause of candidiasis. The clinical presentation varies and can include localized mucocutaneous infections (e.g., oropharyngeal, esophageal, intertriginous, and vulvovaginal candidiasis) and invasive disease (e.g., candidemia, intraabdominal abscess, pericarditis, and meningitis). Candida/Candidiasis).

Allergic rhinitis

• Avoidance of causative allergens (e.g., pollen, dust, animal fur)
• First-line options that may be used orally or as intranasal sprays:
  • 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 (e.g., fexofenadine Fexofenadine Antihistamines, diphenhydramine Diphenhydramine A histamine h1 antagonist used as an antiemetic, antitussive, for dermatoses and pruritus, for hypersensitivity reactions, as a hypnotic, an antiparkinson, and as an ingredient in common cold preparations. It has some undesired antimuscarinic and sedative effects. Antihistamines, desloratadine Desloratadine Antihistamines, cetirizine Cetirizine A potent second-generation histamine h1 antagonist that is effective in the treatment of allergic rhinitis, chronic urticaria, and pollen-induced asthma. Unlike many traditional antihistamines, it does not cause drowsiness or anticholinergic side effects. Antihistamines, loratadine Loratadine A second-generation histamine h1 receptor antagonist used in the treatment of allergic rhinitis and urticaria. Unlike most classical antihistamines (histamine h1 antagonists) it lacks central nervous system depressing effects such as drowsiness. Antihistamines, azelastine Azelastine Antihistamines)
  • Decongestants or sympathomimetics Sympathomimetics Sympathomimetic drugs, also known as adrenergic agonists, mimic the action of the stimulators (î±, β, or dopamine receptors) of the sympathetic autonomic nervous system. Sympathomimetic drugs are classified based on the type of receptors the drugs act on (some agents act on several receptors but 1 is predominate). Sympathomimetic Drugs (e.g., pseudoephedrine, phenylephrine Phenylephrine An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent. Sympathomimetic Drugs)
  • Corticosteroids Corticosteroids Chorioretinitis (e.g., budesonide Budesonide A glucocorticoid used in the management of asthma, the treatment of various skin disorders, and allergic rhinitis. Asthma Drugs, fluticasone Fluticasone A steroid with glucocorticoid receptor activity that is used to manage the symptoms of asthma; allergic rhinitis, and atopic dermatitis. Glucocorticoids) 
  • Anticholinergics Anticholinergics Anticholinergic drugs block the effect of the neurotransmitter acetylcholine at the muscarinic receptors in the central and peripheral nervous systems. Anticholinergic agents inhibit the parasympathetic nervous system, resulting in effects on the smooth muscle in the respiratory tract, vascular system, urinary tract, GI tract, and pupils of the eyes. Anticholinergic Drugs (e.g., ipratropium Ipratropium A muscarinic antagonist structurally related to atropine but often considered safer and more effective for inhalation use. It is used for various bronchial disorders, in rhinitis, and as an antiarrhythmic. Anticholinergic Drugs bromide)
  • Mast cell Mast cell Granulated cells that are found in almost all tissues, most abundantly in the skin and the gastrointestinal tract. Like the basophils, mast cells contain large amounts of histamine and heparin. Unlike basophils, mast cells normally remain in the tissues and do not circulate in the blood. Mast cells, derived from the bone marrow stem cells, are regulated by the stem cell factor. Angioedema stabilizers (e.g., cromolyn Cromolyn Asthma Drugs sodium Sodium A member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23. Hyponatremia nasal spray)
• Second-line options:
  • Leukotriene Leukotriene Asthma Drugs 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 antagonists (e.g., montelukast Montelukast Asthma Drugs) 
  • Immunotherapy (e.g., controlled exposure Exposure ABCDE Assessment to gradually increasing doses of the allergen to downregulate the IgE IgE An immunoglobulin associated with mast cells. Overexpression has been associated with allergic hypersensitivity. Immunoglobulins: Types and Functions response) 
  • Resection of hypertrophic nasal turbinates Turbinates The scroll-like bony plates with curved margins on the lateral wall of the nasal cavity. Turbinates, also called nasal concha, increase the surface area of nasal cavity thus providing a mechanism for rapid warming and humidification of air as it passes to the lung. Nose and Nasal Cavity: Anatomy or polyps
  • Nasal saline irrigation

Non-allergic rhinitis

• Correct the underlying cause (e.g., discontinue medication, correct choanal atresia Atresia Hypoplastic Left Heart Syndrome (HLHS), avoid consumption of spicy food and other triggers Triggers Hereditary Angioedema (C1 Esterase Inhibitor Deficiency)).
• First-line medical options:
  • Topical 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 (e.g., azelastine Azelastine Antihistamines)
  • Topical intranasal glucocorticoids Glucocorticoids Glucocorticoids are a class within the corticosteroid family. Glucocorticoids are chemically and functionally similar to endogenous cortisol. There are a wide array of indications, which primarily benefit from the antiinflammatory and immunosuppressive effects of this class of drugs. Glucocorticoids (e.g., fluticasone Fluticasone A steroid with glucocorticoid receptor activity that is used to manage the symptoms of asthma; allergic rhinitis, and atopic dermatitis. Glucocorticoids)
• Second-line medical options:
  • Combination of topical 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 and topical intranasal glucocorticoids Glucocorticoids Glucocorticoids are a class within the corticosteroid family. Glucocorticoids are chemically and functionally similar to endogenous cortisol. There are a wide array of indications, which primarily benefit from the antiinflammatory and immunosuppressive effects of this class of drugs. Glucocorticoids
  • Decongestants or sympathomimetics Sympathomimetics Sympathomimetic drugs, also known as adrenergic agonists, mimic the action of the stimulators (î±, β, or dopamine receptors) of the sympathetic autonomic nervous system. Sympathomimetic drugs are classified based on the type of receptors the drugs act on (some agents act on several receptors but 1 is predominate). Sympathomimetic Drugs (e.g., pseudoephedrine) 
  • Nasal lavage with hypertonic Hypertonic Solutions that have a greater osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation NaCl solution 
  • Resection of hypertrophic nasal turbinates Turbinates The scroll-like bony plates with curved margins on the lateral wall of the nasal cavity. Turbinates, also called nasal concha, increase the surface area of nasal cavity thus providing a mechanism for rapid warming and humidification of air as it passes to the lung. Nose and Nasal Cavity: Anatomy or polyps