Urticaria (Hives)
What are hives (urticaria)?
Hives are a skin condition characterized by raised, red, non-scaly welts of variable size that itch and can appear anywhere on the body. They often arise suddenly and fade on their own within 24 hours, usually leaving no marks, though new wheals may recur. If episodes come and go for less than 6 weeks, this is acute urticaria. If they persist beyond 6 weeks, this is chronic urticaria.
What causes hives?
- Foods, e.g., seafood, certain nuts, preservatives, artificial coloring
- Drug allergy, e.g., antibiotics, pain relievers
- Insect venom allergy, e.g., ants, bees, wasps
- Contact allergens, e.g., latex, animal dander
- Infections—viral, bacterial, fungal, or parasitic—can trigger hives
- Endocrine disorders, e.g., thyroid disease
- Physical factors—abnormal reactions to heat, cold, pressure, sunlight, or exercise
- Certain cancers, e.g., lymphoma
- Autoimmune mechanisms
- Idiopathic (unknown cause)—many patients cannot identify a trigger
How are hives treated?
- Identify and avoid triggers whenever possible
- Use antihistamines; there are short-acting and long-acting options. Some patients respond to a single agent, while others require combination therapy under medical guidance.
- If symptoms are severe and unresponsive to antihistamines, doctors may consider other agents that inhibit the release of inflammatory mediators in the skin.
Patients with acute urticaria who can identify and remove the trigger usually improve within 1–2 weeks with antihistamines. When no cause is found or the trigger cannot be eliminated, the condition may become chronic.
How should you care for yourself if you have hives?
- Avoid known triggers
- Carry an antihistamine and use it promptly when symptoms start
- Avoid scratching to reduce the risk of skin infection
- Take medications exactly as prescribed; watch for side effects and inform your doctor if they occur
- Seek urgent medical care if severe hives occur with chest tightness, breathing difficulty, abdominal pain, facial or eyelid swelling
