Alopecia areata (AA) is the most common cause of non-scarring alopecia. (Hordinsky, 2013).~Although many patients improve spontaneously or respond to standard therapy, in patients with more severe and refractory disease, management can be quite challenging (Messenger et al., 2012 and Kranseler and Sidbury, 2017).~Corticosteroids either topical or intralesional are the most popular medications used to treat this condition. Other therapies such as topical minoxidil (MXD), anthralin, immunotherapy, systemic corticosteroids are also commonly used with variable success (Shumez et al., 2015).~Patients treated with MXD 5% have significant hair growth than placebo. Minoxidil was more effective for patchy alopecia than other types of AA such as ophiasis and alopecia totalis. It was ineffective in alopecia universalis (El-Taib et al., 2017).~In contrast, the incidence of adverse events associated with 10% MXD treatment was higher than with 5% MXD treatment. Therefore, new approaches are required to achieve both expected efficacy and safety (Oaku et al., 2022).~The combination of non-ablative laser and topical MXD can be a good alternative therapy for AA patients, including alopecia totalis and alopecia universalis, without systemic and local side effects (Wang et al., 2019) According to follicle deposition and diffusion experiments, minoxidil nanoemulsions penetrated hair follicles 26 times more efficiently than standard treatment (Cardoso and Barradas, 2020).~To the best our knowledge no previous research studied the effect of nanominoxidil solution in treatment of AA except in animal or compare transepidermal drug delivery versus topical nanominoxidil.
Compare the clinical efficacy, and safety of transepidermal drug delivery of fractional CO2 laser versus microneedling followed by minoxidil 5% application for the treatment of alopecia areata.~Evaluate the efficacy, and safety of minoxidil nanoparticles as a topical treatment of alopecia areata.