Other risk factors include hot humid weather, poor circulation, and diabetes mellitus. The doctor can test scrapings of the nail or the material under the nail for the fungus. The fungus is identified under a microscope or the material is placed on dish with nutrients to see if fungus grows. This must be done because other diseases such as psoriasis or lichen planus can mimic onychomycosis. Onychomycosis never resolves by itself.
Treatment is an antifungal drug, which is taken by mouth for several months.
Treatment is lengthy because of the slow growth of the nail. Side effects of these oral drugs include headaches, rash, nausea, vomiting or stomach upset, and rarely, reversible liver damage or blood disorders. In addition, topical antifungal creams are available, but are less successful when used alone. Surgery may be used with the other methods of treatment but this can be painful and disfiguring. Eventually, the entire nail separates, resulting in partially destroyed, yellow nail.