Drug-induced skin pigmentation is the cause of 10-20% of acquired hyperpigmentation of skin. The pigmentation can be induced by a wide range of drugs, but the most common include non-steroidal anti-inflammatory drugs (NSAIDs), phenytoin, antimalarials, amiodarone, antipsychotics, cytotoxic drugs, tetracyclines, and heavy metals. In some cases, certain drugs can cause a rash called fixed drug eruption, which is followed by localized hyperpigmentation that fades over time.
What causes it?
Some drugs react with melanin, or the pigment in the skin, to form drug-pigment complexes that are often exacerbated by exposure to sunlight. Some drugs induce hypermelanosis, or the accumulation of melanin, as part of a non-specific post-inflammatory change in predisposed individuals. Other drugs can induce pigmentation by directly accumulating and/or reacting with substances that are in the skin. Heavy metals can be deposited in the dermis layer of the skin following damage to blood vessels in the skin. If a sufficient quantity of heavy metals is deposited, a change in skin color can be seen even without a change in melanin quantity.
What is the treatment?
In many cases, discontinuing the drug that caused the skin changes is enough for the pigmentation to start fading over time. However, sometimes pigmentation can last a long time or become permanent. It is very important to wear consistent sun protection as sun exposure can lead to photosensitivity reactions in the pigmented areas.
If the appearance of drug-induced pigmentation is causing negative psychological effects, discuss cosmetic treatment options with our dermatologists.