Digital follow‐up by means of dermatoscopy and reflectance confocal microscopy of actinic keratosis treated with Imiquimod 3.75% cream

Background Imiquimod 3.75% cream (Zyclara ® Meda, Stockholm, Sweden) is a new field‐directed therapy for actinic keratosis ( AK ). Objectives The aim is to evaluate efficacy and the morphologic dynamic changes induced by this treatment by means of dermatoscopy and reflectance confocal microscopy ( RCM ) of imiquimod 3.75% cream for the treatment of AK s of the face or scalp and to evaluate. Methods Thirty‐two patients were treated with Imiquimod 3.75% cream. Demographic parameters, AK ‐ FAS and AKASI scores and side‐effects were collected. RCM and dermatoscopy on one target AK s were performed at each visit. We collected images at baseline (T0), after 1 week from the end of the first 2‐week cycle (T1), after 1 week from the end of the entire treatment (T2) and 2 months after the end of treatment (T3). Results One target representative AK in the selected area of treatment of each patient was analysed. All dermoscopic and confocal parameters were reduced 2 months after the end of the therapy (T3) with a substantial reduction of AKASI and AK ‐ FAS scores, and 17 cases (54.8%) were completely solved. Confocal microscopic analysis showed a reduction of keratinocytes disarray in 77.4% of cases; none showed crusts and parakeratosis. Inflammation was considerably decreased and was observed only in 12.9% of patients at the last visit. This improvement was not assessed on dermatoscopy because of inflammation and background erythema, which adversely influenced the assessments. LSR s were observed in almost all the patients during treatment being more severe after the first cycle of treatment (T1). Conclusions Imiquimod 3.75% cream is effective in treating clinical and subclinical AK s with an easy management of side‐effects. Dermatoscopy and mostly RCM allow non‐invasive monitoring of treatment response in vivo .