Warfarin-induced alopecia.

Earlier reports of the association between oral anticoagulation and alopecia describe a high incidence of this complication (42 to 78 percent). However, judged by its extreme rarity in a survey of eight experienced, busy academic dermatologists in Boston, this association is not common, nor is the assumption that the alopecia tends to occur soon after the administration of warfarin necessarily true. Nevertheless, alopecia persists in the face of continued warfarin administration; the time required for hair to regrow after discontinuation of the drug may be too long to be practical if continued anticoagulation is necessary; the effect of oral substitutes for warfarin is unknown; and alopecia may recur if the patient is rechallenged with warfarin.