dermatologic disorders
Hyperpigmentation
Drug Induced Hyperpigmentation
Changes are usually diffuse but sometimes have drug-specific distribution patterns or hues ( see Table: Hyperpigmentation Effects of Some Drugs and Heavy Metals ). Mechanisms include Increased melanin in the epidermis (tends to be more brown) Increased melanin in the epidermis and high dermis (mostly brown with hints of gray or blue) Increased melanin in the dermis (tends to be more grayish or blue) Dermal deposition of the drug, metabolite, or drug–melanin complexes (usually slate or bluish gray) Drugs may cause secondary hyperpigmentation. For example, focal hyperpigmentation frequently occurs after drug-induced Lichen Planus (also known as lichenoid drug eruption). In fixed drug eruptions, red plaques or blisters form at the same site each time the causative drug is taken; residual postinflammatory hyperpigmentation usually persists, especially in darker skin types. Typical lesions occur on the face (especially the lips), hands, feet, and genitals. Typical inciting drugs include antibiotics (sulfonamides, tetracyclines,trimethoprim, and fluoroquinolones), nonsteroidal anti-inflammatory drugs, and barbiturates. Treatment of drug-induced hyperpigmentation involves stopping the causative drug; the hyperpigmentation fades very slowly in some if not all cases. Because many drugs that cause skin pigmentation also cause Photosensitivity , patients should 