orticaria

Urticaria, commonly known as hives, is a skin condition defined by transient, itchy wheals caused by mast cell degranulation and histamine release in the superficial dermis. Lesions typically last less than 24 hours, but new ones can appear; angioedema may accompany urticaria.

Most cases are acute, lasting less than six weeks. Chronic urticaria persists beyond six weeks. Causes are diverse: allergic reactions to foods or drugs; infections; autoimmune processes; and physical triggers such as dermographism, cold, heat, pressure, or sun exposure. In many cases the cause remains idiopathic.

Pathophysiology involves mast cell activation and mediators leading to edema and pruritus.

Diagnosis is clinical. Tests are not routinely needed, but may be used in persistent cases to assess underlying disease or triggers (e.g., CBC, ESR/CRP, thyroid tests, allergy testing).

Treatment focuses on symptom control and trigger avoidance. First-line therapy uses non-sedating second-generation antihistamines (cetirizine, loratadine, fexofenadine). If needed, the dose can be increased up to fourfold. Short courses of systemic corticosteroids may be used for severe flares. For chronic urticaria unresponsive to antihistamines, options include higher antihistamine dosing, leukotriene receptor antagonists, and omalizumab; cyclosporine is considered in select refractory cases. Epinephrine is essential for anaphylaxis or significant angioedema.

Prognosis varies; most acute urticaria resolves within days to weeks. Chronic urticaria may persist longer but often improves over time with treatment and avoidance of triggers.