The nail apparatus can be involved in several inflammatory skin disorders. Nail abnormalities may be associated with skin changes or isolated. The latter event gives rise to difficulties in diagnosis and choice of therapy. A careful clinical history is mandatory for correct identification of the disease, together with examination of skin and mucous membranes. Dermoscopy and mycology may be necessary for differential diagnosis. Nail biopsy is mandatory in doubtful cases but should be performed in the right area. The most common inflammatory skin disease that may involve the nail is psoriasis, but lichen planus and other less common disorders, such as bullous diseases, may affect the nail epithelia. All these diseases have a chronic course that requires prolonged treatment and often relapse. When the nails are the sole site of involvement, the choice of therapy is very difficult, as it is difficult to use potent drugs for isolated nail disease. Nonetheless, patients are very distressed by these conditions, and this fact should also be considered. Management of these diseases is therefore difficult and requires periodic follow-up.