Vitiligo is a condition in which white spots or patches appear in areas of the skin that have lost melanocytes. Melanocytes are cells that produce melanin, a pigment that gives skin its color. Areas often affected include the face, knees, elbows, hands, feet, and genitalia. Vitiligo lesions are usually flat (macular), irregular in shape, and well defined. The skin texture remains normal.
Vitiligo affects about 1 percent of the U.S. population. Those affected may suffer from social stigmas. But the de-pigmented skin is also very susceptible to sunburn and certain skin cancers.
Although its cause is unknown, genetics and the autoimmune system are suspected to be involved. And while it is associated with pernicious anemia, hyperthyroidism, and Addison’s disease, this article focuses vitiligo that is drug induced (which is not to say that drug-induced vitiligo is mutually exclusive from other types and/or causes).
The mechanism by which drugs or medications can cause vitiligo is not well understood and much more research needs to be done. Currently, however, the leading suggested mechanisms by which vitiligo is drug induced include:
- The drug activates cytotoxic T lymphocytes (a type of white blood cell that performs immune functions) that fight melanocyte antigens
- The drug damages nerves in the sympathetic nervous system (which includes nerves that reach the skin) connected to melanocytes by chemical synapses (nerve connections through which signals are passed by chemical transmitters)
- Direct toxic effects on melanocytes
Drugs/medications that are associated with drug-induced vitiligo include:
- Anticonvulsants such as carbamazepine (CBZ), valproic acid, clonazepam (Klonopin, Rivotril, Rivatril), and phenytoin (Phenytek, Dilantin, Eptoin, Epanutin)
- Antimalarial drugs such as chloroquine and quinine
- Drugs for Parkinson’s disease such as tolcapone and levodopa
- Certain drugs for alopecia (which typically results in scalp hair loss) such as diphencyprone and squaric acid dibutylester
- Others, including interleukin-2 (Aldesleukin, Proleukin), interleukin-4, interferon, infliximab (Remicade), fluphenazine (Prolixin), clofazimine (Lamprene), dopamine, hydroquinone monobenzyl ether ester, ganciclovir (Cytovene, Cymevene), beta-blockers, and insulin lispro (Humalog)
There are several approaches to the management of vitiligo. They include the use of sunscreen, cosmetic coverup, topical glucocorticoids, topical or systemmic photochemotherapy, narrow-band UVB 311 nm exposure, and minigrafting.