Selenium sulfide, also known as selenium disulfide, is a widely used therapeutic available over the counter in shampoo, lotion, and suspension formulations for the treatment of seborrheic dermatitis and other Malassezia-related conditions, such as tinea versicolor. While application of lotion and suspension can cause irritant dermatitis if left on for too long, selenium sulfide products are otherwise typically well-tolerated with a paucity of adverse effects.

Discoloration of the scalp and hair from selenium sulfide shampoo has been rarely reported. It typically presents as orange, red, or red-brown discoloration and has been seen in children and adults. The pathomechanism is thought to be deposition of selenium sulfide powder, which is orange, on the skin. The discolored areas can be removed with an alcohol swab, solidifying the diagnosis. An orange-brown discoloration of nails and lighter-colored hair (blond or gray) has also been reported. One case of green hair discoloration can be found in the literature as well.

It is possible that the compound may also cause a shift to telogen and therefore hair thinning or loss, particularly with intense and prolonged exposure, and it may increase oiliness of the scalp by increasing sebaceous gland secretion and/or size. It may impact the color or longevity of some hair dyes.