Solar urticaria is a rare skin condition characterized by the rapid development of hives or welts after exposure to sunlight. These reactions typically occur within minutes and can last for several hours. Symptoms may include itching, redness, and swelling, primarily affecting areas of the skin that are exposed to sunlight. The exact cause of solar urticaria is not fully understood, but it is believed to involve an abnormal immune response to ultraviolet (UV) light. Treatment options often include avoiding sun exposure, using protective clothing, and taking antihistamines to manage symptoms.