Urticaria in Adult
Alerts and Notices
SynopsisUrticaria is an inflammatory response characterized by wheals (hives), angioedema, or both. It is caused by the release of histamine and other vasoactive substances from mast cells. Urticaria is characterized by superficial swelling, whereas deeper swelling presents as angioedema.
Urticaria can be triggered by a variety of mechanisms, both allergic and nonallergic. Urticaria is categorized as acute (new-onset or recurring episodes of up to 6 weeks' duration) or chronic (recurring episodes lasting longer than 6 weeks).
In half of acute urticaria cases, the inciting factor is never identified; 40% of cases are associated with an upper respiratory infection, 9% with drugs, and 1% with foods. Drugs causing acute urticaria include NSAIDs, radiocontrast media, opiates, and angiotensin-converting enzyme (ACE) inhibitors.
Chronic urticaria is more common in women and individuals aged 40 years and older, whereas acute urticaria is more commonly seen in children. Disease resolves within 2 years in approximately 50% of individuals with chronic urticaria; however, 20% of individuals may have symptoms that persist for more than 10 years. Chronic urticaria is subdivided into chronic inducible urticaria and chronic spontaneous urticaria, based on whether definite triggers exist and can be identified. Chronic inducible urticaria is triggered consistently, reproducibly, and exclusively by a specific stimulus. These stimuli further define chronic inducible urticaria subtypes: symptomatic dermographism, cold urticaria, delayed pressure urticaria, solar urticaria, heat urticaria, and vibratory angioedema are physical urticarias, whereas cholinergic urticaria, contact urticaria, aquagenic urticaria, and adrenergic urticaria are not.
Chronic spontaneous urticaria may be exacerbated by triggers such as NSAIDs, alcohol, and stress, but triggers are not definite, as stimuli do not always produce symptoms. While the cause of chronic spontaneous urticaria is unknown, the presence of mast cell-activating autoantibodies in many patients raises the possibility of an autoimmune origin. It is also associated with other autoimmune conditions, including autoimmune thyroid disease, vitiligo, type 1 diabetes mellitus, rheumatoid arthritis, and autoimmune gastritis.
Other associated factors:
- Acute urticaria – high population density, allergic disease
- Chronic urticaria – hepatitis B virus, hepatitis C virus, Epstein-Barr virus, mycoplasma, systemic lupus erythematosus, neoplasms (especially lymphoreticular cancers and lymphoproliferative cancers), and oral contraceptive pills (OCPs)
- Chronic induced urticaria – environment (temperature, altitude), allergic disease
- Chronic spontaneous urticaria – gastrointestinal tract infection (Helicobacter pylori, bowel parasites) and inflammation (gastritis, reflux esophagitis, cholangitis), bacterial infection of the nasopharynx, cancer, depression, anxiety, and metabolic syndrome
- Vibratory urticaria – mutation in ADGRE2 (EMR2), which affects mast cell function
L50.9 – Urticaria, unspecified
126485001 – Urticaria
Differential Diagnosis & Pitfalls
- Serum sickness / serum sickness-like reaction – Associated with fever, lymphadenopathy, arthralgias, dusky skin lesions, and recent drug (ie, beta-lactam) or sera exposure.
- Urticarial vasculitis – Individual lesions last longer than 24 hours and are associated with pain, purpura, and/or arthralgias or arthritis (joint swelling or refusal to use extremities).
- Mastocytosis (urticaria pigmentosa) – Has persistent yellow-brown macules and plaques that urticate with stroking.
- Bullous pemphigoid and dermatitis herpetiformis may present with urticarial lesions, but individual lesions last longer than 24 hours and progress to vesicles or erosions. These are exceptionally pruritic as well.
- Sweet syndrome (acute febrile neutrophilic dermatosis) – Urticarial plaques lasting over 24 hours, accompanied by fever, leukocytosis, arthralgia, malaise, headache, and myalgia.
- Insect bites (papular urticaria) – Lesions are often excoriated and last longer than 24 hours.
- Immunoglobulin A vasculitis (formerly Henoch-Schönlein purpura) – Associated with fever, edema, palpable purpura, and renal, gastrointestinal, musculoskeletal, and central nervous system disease.
- Erythema multiforme – Fixed for several days, does not respond to antihistamines, and is associated with dusky, necrotic centers (rather than the pale edematous center of urticaria).
- Contact dermatitis (irritant, allergic) – May have an unusual geometric shape correlating to the inciting irritant and often develops blisters. May be secondary to a food allergen.
- Lupus erythematosus – Often with epidermal changes (scaly, atrophic, or ulcerated).
- Herpes zoster – May initially be urticarial, but lesions are painful and evolve into blisters and crusts.
- Erythema annulare centrifugum – Often with epidermal changes (scale), and lesions persist for weeks.
- Wells syndrome (granulomatous dermatitis with eosinophilia / eosinophilic cellulitis)
- Melkersson-Rosenthal syndrome
- Fixed drug eruption
- Exanthematous drug eruption
- Lyme disease
- Erythema marginatum
- Bedbug bite
- Toxocariasis – A common cause of chronic urticaria.
- African trypanosomiasis
- Cryopyrin-associated periodic syndromes – Muckle-Wells syndrome, familial cold autoinflammatory syndrome (familial cold urticaria), and neonatal-onset multisystem inflammatory disease.
- Acquired autoinflammatory syndromes – Schnitzler syndrome, adult onset Still disease, episodic angioedema with eosinophilia (Gleich syndrome), systemic capillary leak syndrome.
- Phospholipase Cg2–associated antibody deficiency – Lifelong cold-induced urticaria with variable antibody deficiency and increased risk for infection, autoimmunity, and granulomatous disease.
- Alpha-gal syndrome – Mammalian meat allergy induced by a tick bite that elicits immunoglobulin E (IgE) antibodies to galactose-alpha-1,3-galactose (alpha-gal), resulting in urticaria, angioedema, and anaphylaxis symptoms 3-6 hours (delayed onset) after ingesting the meat. Implicated tick bites have been noted to be pruritic for 2 or more weeks.
Drug Reaction DataBelow is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.
Urticaria in Adult