Some causes of underarm rash include infection, allergic reaction, and inflammation. Itchy, inflammatory, bacterial, or fungal rashes in your armpit can be mild or severe, short-lived or chronic.

Less commonly, the pain—referred to as axillary pain—may be due to an autoimmune or arterial disease, nerve compression, and malignancies like breast cancer.The diagnosis of armpit pain may involve ...

Other causes of an armpit rash include a yeast infection, psoriasis, or seborrheic dermatitis. Rashes are pesky patches of irritated skin that can affect any part of your body, including your armpits.

Painful armpit lumps are often due to a swollen axillary lymph node under the armpit. This is usually a sign that the body is fighting an infection, but it can sometimes indicate cancer.

Lymph nodes are part of the body’s immune system. A swollen lymph node in the armpit may be a sign of a bacterial or viral infection, an injury, or a serious health condition, such as cancer.