Psoriasis is a chronic immune-mediated inflammatory skin disorder, with a prevalence of 2-3% worldwide. Psoriatic lesions affecting scalp, nails, palms, and soles are considered difficult-to-treat and require specific management. When psoriasis involves these areas, it may be considered more severe even if the lesions are not extensive. Adalimumab (Humira®) is a fully human monoclonal antibody against tumor necrosis factor (TNF), administered via subcutaneous injection. It has already been used in the treatment of adults and children with moderate-to-severe chronic plaque psoriasis. In literature, few studies investigated its efficacy in difficult-to-treat areas, hence we conducted an observational prospective study of 24 weeks to assess it...