Phototoxic reactions result from direct damage to tissue caused by a photoactivated compound. Many compounds have the potential to cause phototoxicity. Most have at least one resonating double bond or an aromatic ring that can absorb radiant energy. Most compounds are activated by wavelengths within the UV-A (320-400 nm) range, although some compounds have a peak absorption within the UV-B or visible range.
162 prospective patients were compared to 172 historical patients. Pill counts correlated well with MEMS data (R=0.498 for 7-day intervals, R=0.872 for intervals >7 days). Treatment completion rates were higher among prospective than historical patients (82.1% vs. 65.1%), primarily due to lower abandonment rates. If you have a sun allergy, your treatment must always begin with the strategies described in the Prevention section. These will reduce your sun exposure and prevent your symptoms from worsening.
Other treatments depend on the specific type of sun allergy: • PMLE — For mild symptoms, either apply cool compresses (such as a cool, damp washcloth) to the areas of itchy rash, or mist your skin with sprays of cool water. You can also try a nonprescription oral (by mouth) antihistamine — such as diphenhydramine or chlorpheniramine (both sold under several brand names) — to relieve itching, or a cream containing cortisone. For more severe symptoms, your doctor may suggest a prescription-strength oral antihistamine or corticosteroid cream. In many cases, five ultraviolet light exposures are given per week over a three-week period. If standard phototherapy fails, your doctor may try a combination of psoralen and ultraviolet light called PUVA; antimalarial drugs; or beta-carotene tablets. Ongoing Research is being done at Sun allergy centres.