Hives (urticaria) are common, itchy, raised welts on the skin. They can be red, pink, or flesh-colored, vary in size, and often appear, change, or disappear quickly. Approximately 20% of the population experiences hives at least once in their lifetime.
Understanding Hives Duration
Hives can persist for a week or longer, though many resolve within days. Hives that resolve within six weeks are acute urticaria. Individual acute welts typically last less than 24 hours, but new ones can continuously appear, giving the impression of a prolonged rash.
Hives lasting six weeks or more, and recurring frequently, are chronic urticaria. Chronic forms may persist for months or years. Their cause is often less clear than acute cases, sometimes stemming from underlying medical conditions or infections rather than immediate allergic reactions.
Acute hives often result from the body’s immune response to various triggers. These include allergic reactions to foods, medications, or insect bites. Environmental factors like pollen or animal dander, and infections such as viral illnesses, are also common causes.
Non-allergic factors can also trigger acute hives. Physical stimuli like pressure, extreme temperatures, sunlight, or exercise can lead to hives. Emotional stress is another potential trigger. Identifying and avoiding these triggers can help manage acute hive outbreaks.
When Persistent Hives Warrant Medical Attention
Seek medical attention for hives if they persist or are accompanied by concerning symptoms. If hives last longer than a week or two, or become chronic (lasting six weeks or more), a doctor’s evaluation is advisable. Persistent hives may indicate an underlying condition requiring diagnosis and management.
Seek immediate medical attention if hives are accompanied by severe symptoms, signaling a serious allergic reaction called anaphylaxis. These include difficulty breathing or wheezing, swelling of the face, lips, tongue, or throat (angioedema), dizziness, or sudden weakness. Anaphylaxis is a life-threatening emergency requiring prompt medical intervention.
Also consult a doctor if hives are painful, accompanied by fever, joint pain, or bruising, as these may suggest a different skin condition or underlying systemic issue. Hives that do not respond to over-the-counter antihistamines or recur frequently without an identifiable cause also warrant professional medical assessment. A healthcare provider can help determine the cause, confirm diagnosis, and recommend effective treatments or further tests.