Red itchy armpits may be caused by eczema, irritant dermatitis or fungal bacterial infections, which can be treated with medication according to the cause and attention to cleanliness and hygiene. 1. Eczema: may be because the armpit skin is moist, with the arm movement heat friction caused by eczema, can be applied topical glycerine lotion, dexamethasone cream, etc. to alleviate the symptoms. 2. irritant dermatitis: due to the armpit is not ventilated, sweating too much, sweat stimulation of local skin dermatitis, resulting in armpit red itch and other symptoms, oral chlorpheniramine maleate and other medications to relieve, pay attention to wear loose clothing, avoid stimulation of the armpits. 3. Fungal and bacterial infections; because the armpits are always warm and humid, suitable for the growth of some fungi and bacteria. The growth of fungi and bacteria will stimulate the skin, making the armpits red and itchy, and may also be accompanied by odor. Topical terbinafine hydrochloride ointment, naftifine ketoconazole ointment, miconazole nitrate ointment and so on can alleviate the symptoms, and usually need to pay attention to personal hygiene, take a shower. All of the above drugs should be used in accordance with medical advice. Red itchy armpits may also be caused by other reasons. If there is obvious discomfort, you should immediately go to the regular hospital for standardized treatment.