Itchy skin is also known as "pruritus." Skin diseases and your skin's reaction to chemicals in hygienic products may cause pruritis in your underarms. Treatment for your itchy underarm skin depends on the underlying cause. See your doctor if your underarm skin itches for more than two weeks or causes so much discomfort that you cannot sleep.
Miliaria rubra is a form of heat rash that may cause itchy underarm skin. You may experience miliaria rubra after exposure to hot and humid environments or if you are confined to bed rest. Red bumps may occur with the itching, and you may experience little or no sweating under your arms. Heat rash occurs when sweat glands in your armpit are clogged and perspiration remains trapped under your skin. Physical activity that causes excessive sweating increases your risk for developing this form of heat rash. Calamine lotion and cool environments can help sooth itching for most cases of heat rash.
Hidradenitis suppurativa is a sweat gland disease that may cause itchy underarm skin. Itchiness many accompany blackheads and tender, red bumps called abscesses. Abscesses grow, break open and leak pus. Tunnels may form under your skin between individual abscesses. Hidradenitis occurs more in African-Americans and people who suffer from acne. Treatment may include antibiotics, anti-inflammatory medicine and surgery in more severe cases. Controlling your weight and wearing lose, breathable clothing may improve hidradenitis suppurativa.
Psoriasis is a skin disease that causes your skin cells to build up rapidly on the surface of your skin. You may develop firm, thick scales and itchy, dry or red patches that can become painful. Inverse psoriasis is a form of psoriasis that can develop in the armpit. Smooth patches of red and swollen skin characterize inverse psoriasis. Excess weight and obesity increase your risk of experiencing this form of psoriasis due to friction and sweating in the folds of your skin.
Antiperspirant and Deodorant
Your skin may react with ingredients in antiperspirant and deodorant and cause itchy underarm skin. These items may also clog your sweat glands and lead to conditions like heat rash and hidradenitis suppurativa. Spray-on antiperspirants and deodorants may be more likely to clog your glands. Roll-on products and products with natural ingredients made for sensitive skin may help you avoid itchy underarm skin. More severe infections may require antibiotics or anti-inflammatory medication.
Dermatitis causes inflammation of your skin and may cause itchy underarms. Dermatitis may occur with redness and skin lesions. Laundry soap, skin soap and detergents can irritate dermatitis. Rubber, perfume, weeds and ingredients in antibiotic creams may cause allergic reactions when they contact your underarm skin. Dry skin may also contribute to dermatitis that causes itchy underarm skin.