Instead, the condition that's causing it needs to be treated. Once the underlying condition is under control, the rash should get better. 9. Inverse Psoriasis Another cause of an armpit rash that’s ...

Armpit pain can be caused by many issues, from muscle strains to swollen lymph nodes. Here are possible causes of underarm ...

Rheumatoid arthritis, an autoimmune inflammatory disease, can cause swelling and inflammation in the shoulder joint and tissues which may manifest as armpit pain, says O’Hare. Psoriasis is a ...

Inverse psoriasis, typically seen in folds of skin under the breast, armpit, or groin. Erythrodermic psoriasis is a rare but serious type of psoriasis that affects almost every body part.