Most underarm rashes can be treated with over-the-counter topical creams and ointments, such as calamine lotion and hydrocortisone, according to Jason Nell of HowStuffWorks. If the rash is caused by an allergic reaction, antihistamine remedies may help to soothe the itching and associated inflammation.
Some irritation and discomfort caused by underarm rashes subsides with the use of nonsteroidal anti-inflammatory drugs, such as ibuprofen and naproxen, explains Nell. People can also prepare an oatmeal bath, and rest in the water to allow the ingredient to combat itchiness and dryness resulting from the rash. It is important to keep the affected area dry so that the rash is not able to fester and spread.
The best treatment for an underarm rash varies according to each patient's specific diagnosis. For this reason, Healthgrades recommends that patients visit their doctor to undergo a thorough analysis and receive a targeted remedy for their outbreaks. Causes for underarm rashes include contact with poison ivy, eczema, insect stings, chemical irritants found in detergents and fragrances, psoriasis and exposure to allergens, such as shellfish and peanuts. Accompanying symptoms help doctors to pinpoint the origin of a rash and may include joint stiffness, headaches, bruising, tenderness, sore throat, swelling, pus, runny nose or sweating. If home remedies do not improve symptoms, and a patient experiences rapid swelling in the face or difficulty breathing, Healthgrades urges the patient to seek emergency medical treatment.