Hidradenitis suppurativa (HS), also known as acne inversa, is an inflammatory skin condition that occurs when hair follicles get blocked, inflamed and sometimes infected. Symptoms include recurrent pus-filled cysts, painful nodules and abscesses that develop in areas like the armpits, groin, buttocks and breasts.
In cases of severe hidradenitis suppurativa, patients may also experience sinus tracts – small tunnels under the skin that can fill with pus.
Even though the exact causes of HS is not known, research shows that flare-ups can be triggered by hormonal changes (such as puberty or oral contraceptives), your environment (high temperatures can cause sweating and friction, which can irritate your follicles), and even your lifestyle. Your risk for developing HS is increased if you have obesity, an autoimmune disorder, or a family history of HS.