Diphenylcyclopropenone

Diphenylcyclopropenone (diphencyprone) is a topically administered drug intended for treating alopecia areata and alopecia totalis. Topical immunotherapy using diphenylcyclopropenone may also be an effective treatment option for recalcitrant warts.

Mechanism of action
Diphenylcyclopropenone acts as a local irritant, triggering a local sensitization. It triggers an immune response that opposes the action of the autoreactive cells that otherwise cause hair loss.

Studies
A study of 41 alopecia areata patients showed significant hair regrowth in 40% at 6 months, being sustained in two thirds of these after a 12-month-follow up-period.

In a 2002 study for the treatment of warts, the responders consisted of 135 individuals (87.7%) that had complete clearance of warts. Reported adverse effects were local and included with pruritus (itching) (15.6%), with blistering (7.1%), and with eczematous reactions (eczema)(14.2%). The majority of the patients tolerated the treatment very well. One patient developed local impetigo (minor infection). Patients had an average of 5 treatments over a 6-month period.