Urticaria in Adult
Urticaria is defined as acute (new-onset or recurring episodes of fewer than 6 weeks' duration) or chronic (recurring episodes lasting longer than 6 weeks). Chronic urticaria is more common in women and middle-aged individuals, whereas acute urticaria is more commonly seen in children. Disease resolves within 12 months in approximately 50% of adults with chronic idiopathic urticaria; however, 20% of patients may have symptoms that persist for more than 20 years.
Urticaria can be triggered by a variety of mechanisms, both allergic and nonallergic.
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 aspirin, NSAIDs, morphine and codeine, penicillin and its derivatives, cephalosporins, sulfa, streptomycin, tetracycline, griseofulvin, blood products, radiographic contrast media, angiotensin-converting enzyme inhibitors, and sulfonylureas. Acute urticaria may also be seen as part of anaphylaxis.
Chronic urticaria may be autoimmune, induced by physical stimuli, or idiopathic. NSAIDs, foods, alcohol, stress, and infections may aggravate chronic urticaria but are rarely the cause.
Chronic spontaneous urticaria may be associated with other autoimmune conditions including autoimmune thyroid disease, vitiligo, insulin-dependent diabetes, rheumatoid arthritis, and pernicious anemia.
Other Associated Factors:
- Systemic illnesses such as infections, collagen vascular diseases, neoplasia, endocrine disorders, and blood dyscrasias
- Environmental stimuli such as insect stings (papular urticaria) and inhalants (pollen, spores, animal dander, perfumes, detergents)
- Foods such as strawberries, nuts, eggs, and shellfish
- Inducible stimuli – mechanical stimuli (dermatographism, delayed pressure, vibratory), temperature change (heat, cold), sweating or stress (cholinergic, adrenergic, exercise-induced), contact, solar, aquagenic. Vibratory urticaria has been associated with a mutation in ADGRE2 (EMR2), which affects mast cell function.
- Helicobacter pylori gastritis – patients may undergo remission of chronic urticaria with treatment
- Parasitic infections – intestinal strongyloidiasis, gastric Anisakis simplex
The presence of angioedema without wheals should raise suspicion for hereditary angioedema.
Tick bites from some Amblyomma and Ixodes (and possibly Haemaphysalis) species have been associated with the subsequent development of allergies to mammalian meat (eg, beef, pork) in a small number of patients. It is thought that the allergy is mediated by induced IgE antibodies to alpha-gal (galactose-alpha-1,3-galactose), a mammalian oligosaccharide. Individuals with elevated IgE titers to alpha-gal have experienced urticaria, angioedema, and anaphylaxis symptoms either immediately or 3-6 hours (delayed onset) after ingesting mammalian meat (alpha-gal syndrome). Exactly how the tick bite leads to development of this allergy is unclear. Implicated tick bites have been noted to itch for 2 or more weeks. A blood test for these IgE antibodies exists.
Urticaria is rarely a paraneoplastic syndrome except in the association of cold urticaria as a result of cryoglobulins associated with myeloma or lymphoma. Cold urticaria without cryoglobulins has been reported in human immunodeficiency virus (HIV)-infected individuals.
Related topics: contact urticaria, cholinergic urticaria, physical urticaria, cold urticaria, dermographism, PUPPP, urticarial vasculitis, urticaria pigmentosa, angioedema, anaphylaxis
L50.9 – Urticaria, unspecified
126485001 – Urticaria
Diseases with urticarial lesions include:
- 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.
- Immunoglobulin A vasculitis (formerly Henoch-Schönlein purpura) – Associated with fever, edema, palpable purpura, and renal, gastrointestinal, musculoskeletal, and central nervous system disease.
- 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.
- 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.
- Alpha-gal syndrome
- Angioedema – Edema of the subcutaneous or submucosal tissues rather than edema of the dermis with urticaria. It is not pruritic and commonly affects the face (eyelids, earlobes, lips); familial angioedema usually does not have individual small hives.
- Erythema multiforme – Fixed for several days, does not respond to antihistamines, and associated with dusky, necrotic centers (rather than the pale edematous center of urticaria).
- Papular urticaria / insect bites – Often excoriated and lasts longer than 24 hours.
- Dermatographism may mimic urticaria and is induced by firmly stroking the skin. It lasts from 0.5-2 hours.
- 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.
- Fixed drug eruption
- Exanthematous drug eruption
- Lyme disease
- Erythema marginatum
- Bedbug bite
- Toxocariasis – A common cause of chronic urticaria.
- African trypanosomiasis