PUVA treatment involves taking a psoralen-light sensative drug and then undergoing a short exposure to UVA which is a long wave ultraviolet light.

Some patients do not respond to UVA treatment. It is estimated that the success rate is somewhere between 40-60 percent. The more recent the hair loss the more likely a response to treatment. Treatment normally takes between 3-6 months with sessions 2-3 times per week. Treatment time is about 3-5 minutes.