Hidradenitis suppurativa in the armpit of a 51 year old Hispanic female patient that is improving with infliximab treatment. Hidradenitis suppurativa, also known as acne inversa, is caused by the blockage of the apocrine glands typically found in the armpits, buttocks, groin and back. Apocrine glands are specialised sweat glands that open into a hair follicle before reaching the skin. The glands become blocked due to overactivity, giving rise to inflammation, infection and abscess formation. Infliximab is an immunosuppressant anti-inflammatory drug used to treat various diseases, including hidradenitis suppurativa.