If the skin on the chest is itchy, consider the following diseases: 1. sweat spot: a skin disease caused by a fungal infection of Malassezia species, which can be treated clinically with topical terbinafine hydrochloride gel or bifenazole ointment, and oral psoralen Xantha fever capsules and itraconazole capsules. 2. eczema: an itchy rash accompanied by erythema, papules and other rash manifestations. The clinical treatment can be oral olopatadine hydrochloride tablets or fexofenadine hydrochloride tablets with compound glycopyrrolate capsules and topical hydrocortisone butyrate ointment mixed with butyl flufenamic acid ointment. 3, folliculitis: is due to bacterial infection, can be oral doxycycline capsules, topical fusidic acid ointment or ofloxacin gel topical application.