Hidradenitis suppurativa is inflammation of the apocrine sweat glands, resulting in scarring, inflammation, and painful accumulations of pus under the skin.
Hidradenitis suppurativa develops in some people after puberty because the apocrine sweat glands (the specialized sweat glands under the arms, in the groin, and around the nipples and anus) are chronically blocked. Doctors do not know why the blockage occurs, but it is not related to the use of deodorants or powders or to underarm shaving. The blockage causes the glands to swell and rupture, sometimes leading to infection by various bacteria. The abscesses (pus-filled pockets) that result are tender, painful, and foul smelling and tend to recur. After several recurrences, the skin in the area becomes thick and scarred. Often, permanent channels (sinus tracts) form between the abscess and the skin surface and drain pus.
Hidradenitis suppurativa may cause only a few abscesses and be mild or may cause many abscesses and sinus tracts and be severe.
Hidradenitis suppurativa resembles common skin abscesses. A doctor makes the diagnosis based on the location of the abscesses and on the fact that they recur often. Doctors sometimes take samples of pus from deep abscesses and have the bacteria identified by a laboratory (culture).
For people with mild cases, a doctor injects corticosteroids into the area and prescribes zinc and antibiotics, such as tetracycline or erythromycin, to be taken by mouth (orally). Clindamycin and resorcinol applied to the skin (topically) are also effective. For people with moderate cases, a doctor gives oral antibiotics that are taken for a longer period (2 to 3 months) and may cut open the abscesses to drain the pus. Doctors may give women drugs that block the effects of male sex hormones, such as oral contraceptives, spironolactone, or finasteride. Sinus tracts are opened and drained. For people with severe cases, a doctor gives infliximab (by vein), adalimumab (by injection), or isotretinoin (by mouth) to reduce inflammation. If the disorder persists, a doctor cuts out the involved area and then repairs the skin or does a skin graft. Laser treatment has also been used.
Although it will not cure the condition, all people with hidradenitis suppurativa should maintain good skin hygiene and minimize injury by treating the skin gently. Psychologic support and avoiding a high-glycemic index diet may help.