Urticaria (Hives): Causes, Symptoms & Treatment

Urticaria, commonly known as hives, is a skin condition characterized by itchy, raised welts (wheals) that can appear anywhere on the body. The welts vary in size, may join together to form larger areas, and typically appear and disappear within hours, often migrating to different locations. Hives are very common, affecting up to 20% of people at some point in their lives.

• Acute urticaria: Episodes lasting less than 6 weeks; often triggered by an identifiable cause
• Chronic urticaria: Episodes occurring most days for more than 6 weeks; cause often unknown (chronic spontaneous urticaria)

Acute urticaria:

• Allergic reactions to foods (shellfish, nuts, eggs, milk)
• Medications (antibiotics, NSAIDs, ACE inhibitors)
• Insect stings or bites
• Infections (viral upper respiratory infections are common in children)
• Contact with allergens (latex, animal dander)

Chronic urticaria:

• Often no identifiable cause (chronic spontaneous/idiopathic urticaria)
• Autoimmune processes (antibodies against IgE or its receptor)
• Physical triggers: pressure, cold, heat, sunlight, vibration, exercise (physical urticaria)
• Stress (can worsen symptoms)
• Rarely: thyroid disease or other autoimmune conditions

• Raised, red or skin-colored welts (wheals) that are intensely itchy
• Welts that change shape, move to different locations, and resolve within 24 hours
• Swelling beneath the skin surface (angioedema), especially around the eyes, lips, hands, or feet
• Symptoms may be worse at night

First-line -- non-sedating antihistamines:

• Cetirizine, loratadine, fexofenadine, desloratadine, or levocetirizine
• May be increased to up to 4 times the standard dose if standard dosing is inadequate

Second-line (if antihistamines are insufficient):

• Omalizumab (Xolair): Anti-IgE monoclonal antibody -- highly effective for chronic urticaria unresponsive to antihistamines
• Short courses of oral corticosteroids for severe flares only (not for long-term use)
• Cyclosporine for severe refractory cases

Self-care:

• Avoid known triggers
• Wear loose-fitting clothing
• Apply cool compresses to itchy areas
• Avoid hot showers and baths
• Manage stress

See a doctor if hives last more than a few days, recur frequently, are accompanied by significant angioedema, or do not respond to over-the-counter antihistamines. Seek emergency care for any signs of anaphylaxis.