Methods are disclosed for administering electromagnetic radiation (EMR), which may include filtering EMR from part of the EMR spectrum while allowing passage of EMR at a desired wavelength range. Uses may include the treatment of such conditions as psoriasis, vitiligo, pruritus, acne, vitamin-D deficiency and atopic dermatitis. Topical creams, sprays, or other compositions may be used, with or without dosimeters, or in conjunction with an application, which calculates local UV exposure and other factors relating to dosage.
