Understanding Hives: Causes, Symptoms, and Expected Duration

Urticaria (Hives): Clinical Course and Management

Hives are transient, pruritic wheals caused by mast cell degranulation and histamine release.

Typical Course

• Acute urticaria: <6 weeks; 80% resolve spontaneously. Individual wheals last <24 hrs.
• Chronic urticaria: ≥6 weeks; often autoimmune (anti-FcεRI/IgE autoantibodies); may persist months-years.

Clinical Features

• Erythematous, edematous papules/plaques with central pallor.
• Intense pruritus; burning/stinging possible.
• Migratory — lesions appear/resolve in different locations.
• Angioedema (deep swelling) in 40% — lips, eyelids, extremities, genitalia.

Common Triggers

• Allergic: Foods (nuts, shellfish, eggs), medications (penicillin, NSAIDs), insect stings, latex.
• Physical: Dermatographism, cold, heat, pressure, solar, vibration, aquagenic.
• Infections: Viral (URI, hepatitis), bacterial (strep), parasitic.
• Autoimmune: Thyroid disease, lupus, vasculitis.
• Idiopathic: Majority of chronic cases.

Treatment Ladder

1. Second-gen H1 antihistamines: Cetirizine, loratadine, fexofenadine (standard dose → up to 4×).
2. Add H2 blocker (famotidine) or leukotriene antagonist (montelukast).
3. Short-course oral corticosteroids for flares (avoid chronic).
4. Omalizumab (anti-IgE): FDA-approved for chronic spontaneous urticaria refractory to antihistamines.
5. Immunosuppressants: Cyclosporine, mycophenolate (specialist only).

Emergency: Anaphylaxis

If hives + dyspnea, stridor, hypotension, abdominal pain, syncope → epinephrine IM + 911.

Identify and avoid triggers; keep symptom diary; follow up if chronic.