The itchy inside of one ear may be caused by fungal otitis externa, otitis externa eczema, otitis externa and other diseases. 1. Fungal otitis externa: Fungal otitis externa is caused by fungal infection, patients will appear in the ear itchy, stuffy feeling, a small amount of watery secretion and other symptoms, so the patient will appear in one ear itchy symptoms. 2. Eczema of the outer ear: the cause of eczema of the outer ear is not clear, may be due to perverse reactions and systemic factors. The main symptoms of patients include skin papules, intense itching, ear pain, flaking, etc., which often lead to the symptoms of itching inside one ear. 3. Otitis externa: Otitis externa is mainly caused by infection or external environmental stimuli. Patients will have symptoms such as oozing, flaking, itching and pain in the skin of the external auditory canal, which may also lead to the manifestation of itching inside one ear. The itchiness in one ear may be caused by excessive cerumen accumulation, or it may be caused by diseases. Patients should pay attention to ear hygiene in daily life and seek medical attention when discomfort occurs.