Vitilen is a photosensitizer, prescribed for vitiligo in combination with controlled doses of ultraviolet A (UVA) or sunlight. It is also used for psoriasis, seborrhea. It works by making the skin more sensitive to UV light. It is a naturally occurring substance that is reactive to light. Vitilen is used in combination with UVA light therapy to treat severe psoriasis. Vitilen is usually given after other psoriasis medicines have been tried without success.