Hives: Clinical Meaning

Chronic Urticaria (Chronic Hives)

Chronic urticaria is characterized by recurrent hives lasting more than 6 weeks, causing intensely itchy wheals. In most cases no specific trigger is identified (chronic spontaneous urticaria); non-sedating antihistamines are first-line treatment.

Mast Cell Activation Syndrome

MCAS involves recurrent episodes of mast cell mediator release causing allergic-type symptoms (flushing, urticaria, hypotension, GI symptoms, anaphylaxis) without consistent triggers. Antihistamines and mast cell stabilizers are the foundation of treatment.

Anaphylaxis

Anaphylaxis is a severe, life-threatening allergic reaction requiring immediate emergency treatment with epinephrine. Common triggers include foods, insect stings, medications, and latex.

Food Allergy

Food allergies are immune system reactions that occur after eating a specific food. Even trace amounts can trigger signs and symptoms, including digestive problems, hives, or swollen airways.

Acute Urticaria (Hives)

Acute urticaria is a sudden-onset allergic skin reaction causing raised, itchy welts. It usually resolves within 6 weeks and can be triggered by foods, medications, infections, or insect bites.

Mast Cell Activation Syndrome

Mast cell activation syndrome causes recurring episodes of anaphylaxis-like symptoms due to inappropriate mast cell activation. Diagnosis requires demonstration of abnormal mediator release.