PUVA is a treatment method currently used for various skin diseases such as psoriasis, vitiligo, atopic eczema, severe lichen planus, alopecia universalis, chronic itching, parapsoriasis, and mycosis fungoides (a type of skin cancer). This treatment is based on the principle of taking psoralen orally as a tablet, which sensitizes the skin and eyes to sunlight and regulates the functioning of the immune system, followed by exposure to artificial ultraviolet A (UVA) light.