Hives

Hives (urticaria) are raised, itchy red or pale wheals that appear suddenly and usually fade within hours — though they may keep coming in different places for days or weeks. Most hives are harmless. The danger is when they come with throat or lip swelling or breathing difficulty (anaphylaxis).

Two patterns

• Acute urticaria — lasts under 6 weeks. Usually triggered by a viral infection, food, drug, or insect bite.
• Chronic urticaria — comes and goes for more than 6 weeks. Often no specific cause is found; it is driven by the immune system, not "an allergy".

Common triggers

• Drugs — antibiotics (especially penicillins, cephalosporins, sulfa), pain-relievers (NSAIDs, aspirin), contrast dyes.
• Foods — shellfish, eggs, peanuts, tree nuts, fish, certain fruits.
• Infections — common viruses in children; hepatitis, H. pylori in adults.
• Physical — pressure, cold, heat, exercise, sunlight, sweat.
• Stress can trigger or worsen it.

Red flags — emergency (dial 112)

• Swelling of lips, tongue, face, or throat.
• Difficulty breathing, wheeze, hoarseness.
• Dizziness, collapse, rapid heart rate.
• Widespread hives with vomiting/abdominal pain after a drug, food, or insect bite — likely anaphylaxis. Use an adrenaline auto-injector if available and go to hospital immediately.

Treatment

• Non-drowsy second-generation antihistamines are the mainstay — often at higher-than-routine doses for chronic urticaria, under a doctor.
• Avoid the trigger if known.
• Cool compresses; avoid hot baths, tight clothing, and alcohol during flares.
• Short steroid courses only for severe acute attacks.
• Resistant chronic hives: anti-IgE biologic class and other targeted options at a specialist.
• Stop suspected trigger drugs and tell every future doctor about the reaction — note it in a medical records app or card.