What is hidradenitis suppurativa?

Hidradenitis suppurativa is a chronic, recurrent, and painful disease in which there is inflammation in areas of the apocrine sweat glands. These glands are found mainly in the armpits and groins. Within hidradenitis there is a blockage of the hair follicles. This causes a mixture of boil-like lumps, areas leaking pus, and scarring.

Hidradenitis tends to begin in early life, and is more common in women, black and Mediterranean people. It affects about 1% of the population.

What causes hidradenitis suppurativa?

It is still not clear why some people get this disease, but blockage of the pores plays a part. As the secretions cannot escape, the hair follicles may swell up and burst, or become infected.

Contributory factors include the following:

  • Hormones may be involved in the control of apocrine sweat glands and certainly play a part in the disease. Hidradenitis suppurativa affects women more than men. It does not start before puberty or after the menopause. It may get better during pregnancy, but is often worse before menstrual periods. Some patients do well with hormone treatments (see below).
  • Bacteria play a part too, but a variety of germs, and not just one special type, is found in the spots. It is not clear whether they cause the disease, or just flourish within it.
  • The immune system is involved in some way with the severity of hidradenitis and treatments that reduce the immune system activity have been helpful in occasional cases (see below).
  • Hidradenitis could be also linked to the bowel condition Crohn’s disease, especially if it involves the groins and the skin near the anus.
  • There may be a link with acne and pilonidal sinus (a chronic abscess at the base of the spine).
  • Smoking and obesity do not cause hidradenitis, but are strongly associated with it and may make it worse.
  • Poor hygiene does not cause hidradenitis suppurativa.

What are the symptoms of hidradenitis suppurativa?

Hidradenitis suppurativa is usually painful, and the lumps hurt if they are pressed. Discharge of pus can be a problem, requiring daily dressings. Hidradenitis can have severe psychological effects such as depression, and can rarely be associated with inflammation of the joints (arthritis).

The main areas affected are the armpits, and the skin of the groin, genital and pubic regions. The skin around the anus, the buttocks, thighs, and breasts can give trouble too.

In the affected areas, the skin shows a variable mixture of blackheads, red lumps looking like boils, pus spots, cysts, and areas that constantly leak pus (sinuses). As time goes by, more and more scarring appears.

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