Fungal infection. View of the discoloured toenail of a patient midway through a three month course of treatment for a fungal infection of the toenail (tinea unguium, or onychomycosis). The new growth of the nail (at its base) is not discoloured by the fungus. Tineal infections are caused by a group of fungi called the dermatophytes. Tinea is usually treated with antifungal drugs in the form of creams or ointments, however for widespread infections, the drug is taken in tablet form. Treatment may be continued for some time after the symptoms have subsided to totally eradicate the fungi and to prevent a recurrence.