The causes of ringworm on the legs are tinea corporis and psoriasis caused by fungal infections. The western medical name for psoriasis is neurodermatitis or psoriasis, and there are different options for treatment, as follows: 1. Tinea corporis: You can have a fungal test before treatment, and if the fungus is positive, you need antifungal treatment, such as topical terbinafine hydrochloride ointment, luliconazole ointment, clotrimazole ointment, miconazole nitrate ointment, or naphthalene If the fungus is positive, antifungal treatment is needed, such as topical application of terbinafine hydrochloride ointment, luliconazole ointment, clotrimazole ointment, miconazole nitrate ointment or naftifine ketoconazole ointment, and oral administration of terbinafine hydrochloride tablets or itraconazole capsules; 2.