Aurinkoihottuma

Aurinkoihottuma, also known as solar urticaria, is a rare condition characterized by the development of hives (urticaria) upon exposure to ultraviolet (UV) radiation from sunlight. The reaction typically appears within minutes of sun exposure and can cause itching, redness, and swelling in the affected areas. The severity of the rash can vary, from mild discomfort to severe blistering and pain. Triggers are primarily UV-A rays, although UV-B rays can also play a role in some individuals.

The exact cause of aurinkoihottuma is not fully understood, but it is believed to be an immune system response. In susceptible individuals, UV radiation may interact with certain substances in the skin, leading to the release of histamine and other inflammatory mediators. This triggers the characteristic hive formation. Diagnosis is usually made through a phototesting procedure, where small areas of skin are exposed to controlled doses of UV light to reproduce the reaction.

Treatment focuses on minimizing sun exposure and managing symptoms. This can include wearing protective clothing, using broad-spectrum sunscreens with high SPF, and avoiding peak sun hours. Antihistamines are often prescribed to alleviate itching and reduce the size and duration of the hives. In more severe cases, phototherapy with controlled doses of UV light may be used to desensitize the skin to sunlight, a process known as PUVA therapy. Aurinkoihottuma can significantly impact an individual's quality of life, necessitating careful management and avoidance of triggers.