Hezel S., Schmook T., Nindl I., Mandt N., Röwert J., Sterry W., Stockfleth E.

Department of Dermatology, Charité, University Hospital, D-10117 Berlin, Germany

Objective: Alopecia areata is an autoimmune condition against hair follicles, which results in patchy hair loss on the scalp. Progression may lead to a complete loss of hair on the scalp (alopecia totalis) and potentially cover the whole body (alopecia universalis). Alopecia areata affects approximately 4.6 million individuals in the United States. Incidence rates vary 0.1 % to 1.7%. Aetiopathogenesis is not completely clarified, but genetic predisposition has been verified. Pathohistology shows chronic inflammation and T-cell infiltration of lesional hair follicles. Th1-cytokines are increased (interleukin (IL)-1beta, IL-2, interferon (IFN) gamma, tumour necrosis factor (TNF) alpha). Clinically established therapeutic options include glucocorticoids, dithranol, and contact sensitizers (diphenylcyclopropenone, squaric acid dibutylester). Alopecia areata as an immunologic disorder offers the possibility for topical treatment with immune response modifiers (IRM) as re-immunobalancing drugs. Imiquimod is a member of IRM which stimulates the immune response via toll-like receptor (TLR) 7 by induction, synthesis and release of cytokines of the cellular immunity (IFN alpha, IL-1, IL-6, IL-12, TNF alpha).

Patients and Methods: We investigated the clinical efficacy of topical imiquimod for the treatment of alopecia areata in six alopecia areata totalis patients. All of these patients (4 women, 2 men) have been affected for at least 2 years without any regression. Imiquimod 5% cream was applied sparingly on the alopecic regions 3 times a week overnight and removed by washing in the morning. The duration of treatment was sixteen weeks.

Results: After six weeks of topical treatment with imiquimod 5% cream we observed the beginning of hair regrowth in four of the six patients. No side-effects like local erythema, itching or any other signs of inflammation were observed. Hair growth augmented under continuing application over a period of sixteen weeks. Four weeks after end of treatment, all patients lost their regrown hair.

Conclusion: In patients with alopecia areata totalis imiquimod 5 % cream is a safe, promising and at home applicable therapy. Further investigations such as analysis of hair growth in vivo with digital image analysis (TrichoScan) and analysis of toll-like receptor 7 expression during and after end of treatment will be carried out.