Hidradenitis suppurativa's chronic symptoms can cause debilitating discomfort and pain in patients. Though some individuals may experience more severe symptoms than others, the most common signs of HS include the presence of abscesses -- inflamed pus-filled formations, boils, bumplike nodules under the skin, cysts, lesions and itchy patches of blackheads [sources: Slade et al.; Mayo Clinic Staff]. Bacteria on the surface of the skin often cause HS secretions to smell unpleasant.
To get a better feel for where HS develops, think of where the body produces sweat: in arm pits, groin areas, and the anal and buttocks areas. The disease sometimes flares up in skin folds, along the waist, around the nape of the neck, on the scalp, on the eyelids, behind the ears, around the inner thighs and under the breasts in women.
Generally speaking, symptoms of HS are at their worst 10 to 15 years after the onset of the disease [source: Hidradenitis Suppurativa Foundation]. Since HS symptoms can appear and disappear for years at a time, people living with HS experience cycles marked by the formation of skin lesions, suppuration (the secretion of pus) and healing. As you can imagine, such continual remodeling of the skin can eventually lead to irreversible damage and deep tissue scarring.
Over time, people with HS develop pathways, or sinuses, underneath the skin that connect pus-filled formations in an affected area. Unlike facial sinuses, these sinuses are abnormal and transport pus throughout an area of affected skin.
Despite HS sharing a few symptoms with acne and possessing the name "acne inversa," the disease poses more serious health and social risks than acne. The chronic recurrence of symptoms on the same places of the body sets HS apart from other skin conditions that may result from a one-time infection instead. For instance, the recurring presence of HS symptoms in both armpits for years at a time is more likely to be diagnosed as HS than a brief bout of lesions in one arm pit.
Now that we know more about what hidradenitis suppurativa looks like, learn about possible causes of the disease on the next page.