Patients with itching in the left ear may most often have a condition called eczema of the left ear canal, or may have a mold infection in the left ear canal. Eczema in the ear canal often occurs due to repeated water ingress and humidity in the ear, or being in a humid space for a long period of time. In some patients, the skin of the ear canal is repeatedly stimulated by tears, sweat, and inflammatory secretions, which can lead to itching and eczema. Some patients may also use antibiotic ear drops for too long, or use unclean tools to dig their ears in public places, causing cross-infection, which may lead to the formation of mycotic infections in the ear canal and cause more obvious itching of the ear.