Ringworm is caused by a fungal infection and should not be treated with dexamethasone. The causative organisms of ringworm are mostly Trichophyton rubrum, Trichophyton spp. or Microsporum canis, and Trichophyton floccosum. In clinical treatment, antifungal treatment can be done with itraconazole capsules combined with fluconazole capsules, topical application of bifenoconazole ointment, amorolfine hydrochloride, and wet application of compound Phellodendron jock itch application if the rash is bright red in color. Dexamethasone is a glucocorticoid drug that, if applied to the ringworm area, can cause atypical ringworm to develop, with blurred borders and increased itching. If atypical ringworm develops, trimethoprim ointment can be applied for both anti-allergic and antifungal treatment.