What should you know about aquagenic urticaria?

Sweat, rain, bathing, or swimming may provoke a reaction. A dermatologist usually makes the diagnosis from the history and a supervised water-contact test while excluding other causes of water-related itching or rash.

People with aquagenic urticaria typically develop pinpoint raised welts with surrounding redness and itching after water touches the skin. The trunk and upper arms are often involved, while the palms and soles may remain clear.

The condition is different from an allergy to substances added to water and from aquagenic pruritus, which causes itching without visible welts. Photographs taken during a flare can help the dermatologist see a reaction that has faded before the appointment.

Keep a record of exposures, timing, visible changes, and associated swelling. Until assessed, shorter showers, gentle drying, and a bland barrier product may reduce discomfort, but complete avoidance of water is neither practical nor appropriate.

A clinician may recommend a non-sedating oral antihistamine and adjust the plan according to response. Do not start repeated corticosteroid courses or increase medicine doses without medical direction; persistent symptoms may require confirmation of the diagnosis and a tailored strategy.

Arrange a dermatology review when water repeatedly causes welts, itching interferes with washing or exercise, or the pattern is changing. Assessment is also appropriate when a rash occurs without water exposure, because another diagnosis may be responsible.

Call emergency services for breathing difficulty, throat tightness, faintness, confusion, or rapidly worsening tongue or facial swelling. These warning signs require urgent attention whether or not water was the apparent trigger.

Ask how the diagnosis will be confirmed, whether another physical urticaria or skin disorder could explain the reaction, and which medication plan fits your health history. Clarify what to do before swimming, exercise, or unavoidable prolonged water exposure and which swelling symptoms should trigger emergency action.