Low-dose oral isotretinoin in the treatment of recalcitrant facial flat warts: A clinical case and review of literature.

Background and Aims: The treatment of recalcitrant facial flat warts has always been challenging for dermatologists. The pain related to the application of the different treatments, side effects and costs are determining factors in the choice of therapy. To date, it is known that oral isotretinoin administered at a dose of 0.5 mg/kg/day is effective and safe; However, the different adverse effects reported have a dose-dependent behavior and they could limit their use. Our aim is to assess the effect of low-doses of oral isotretinoin to reducing side effects in the complete removal of recalcitrant facial flat warts and the current evidence in this regard. Methods: An extensive literature review was conducted to identify articles relating to low doses of oral isotretinoin for recalcitrant flat warts treatment, regardless of design up to May 2023. Results: The literature search yielded eight articles of 324 reviewed meeting criteria. Isotretinoin was administered in doses of 0.1-0.5 mg/kg/day. Complete elimination of the lesions occurred in 65.13% of the patients and a partial response in 19.26%. Four relapses were documented at the 4-month follow-up. The most frequent adverse effect was cheilitis. Conclusion: We might consider low doses of oral isotretinoin for the treatment of recalcitrant facial flat warts in which side effects need to be reduced. However, current published works have several limitations, including small sample sizes, lack of control group and follow-up periods. Larger, randomized, controlled studies are needed to verify the efficacy and safety of different doses of isotretinoin.