What is hidradenitis suppurativa?
Hidradenitis suppurativa is a long term, recurrent, and painful disease in which there is inflammation (redness, tenderness and swelling) in areas of skin containing apocrine sweat glands. These glands are found mainly in the armpits, breasts and groins. Within HS there is a blockage of the hair follicles. This causes a mixture of boil-like lumps, areas leaking pus, and scarring.
Hidradenitis suppurativa tends to begin around puberty age, and is more common in women. It is estimated to affect about 1% of the population.
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What causes hidradenitis suppurativa?
It is still not clear why some people get this disease, but it is thought the inflamed spots or lumps develop when there is a blockage of the hair follicles. As the fluid or pus in the spots and lumps cannot escape, the hair follicles may swell up and burst, or may form abscesses and become severely infected.
Contributory factors include the following:
- Hormones may be involved in the control of apocrine sweat glands and might play a part in the disease. In women, HS may be worse before menstrual periods.Some patients may benefit from hormone treatments (see below).
- Bacteria (germs) that normally live on the skin may become trapped in the blocked gland or hair follicle. It is not clear whether the cause the disease or just contribute to the inflammation.
- The immune system is involved in producing inflammation and treatments that reduce the immune system activity may be helpful (see below).
- In a few people with HS there is a link to the bowel condition Crohn’s disease.
- There may be a link with acne and pilonidal sinus (a chronic abscess at the base of the spine).
- Smoking and obesity are linked with HS, but the condition can also affect non-smokers of normal weight.
- Poor hygiene does not cause hidradenitis suppurativa.
Is hidradenitis suppurativa hereditary?
Hidradenitis suppurativa runs in the families of about one third of those with the condition.
Is hidradenitis suppurativa contagious?
No, it can’t be passed on to another person by contact.
What are the symptoms of hidradenitis suppurativa?
Hidradenitis suppurativa is usually very painful, and the abscesses are painful to the touch. Discharge of pus can be a problem, and may require daily dressings. Hidradenitis suppurativa can have a severe psychological effect such as depression, and can sometimes 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 also be affected.
In the affected areas, the early stage of HS presents itself where the skin shows a variable mixture of blackheads and abscesses which consist of red lumps looking like boils, pus spots, and cysts. In the later stages of HS tunnels under the skin that leak pus form and wounds may not heal easily. As time goes by, more and more scarring appears.
How will hidradenitis suppurativa be diagnosed?
The diagnosis is usually made by a doctor examining the area, the symptoms and history. There is no specific test on which the diagnosis can be made.The condition is often misdiagnosed initially as a boil, infection or folliculitis; this can result in delayed treatment and progression of the disease with scarring.
Can hidradenitis suppurativa be cured?
No, it usually persists for many years, but can become inactive eventually. Treatment usually helps even though it generally cannot switch the HS off once and for all.
How can hidradenitis suppurativa be treated?
Treatment is tailored for each individual. In general terms, early onset of HS is usually treated medically, whereas more longstanding and severe HS may benefit from surgical intervention, especially if there are various affected sites.
What treatment is available for a sudden flare of HS, such as a new painful boil?
- A warm flannel applied to the affected skin or taking a bath may encourage drainage of pus
- Painkillers, such as non-steroidal anti-inflammatories (NSAIDs), can help with the pain and inflammation
- A course of antibiotics may be needed if there is any evidence of infection
- Surgical treatment to lance a boil (incision & drainage of the pus)
- A steroid injection into the boil is sometimes considered by dermatologists
Medical treatment to try to prevent flares of HS:
- Antibacterial lotions and washes: Patients are frequently prescribed an antiseptic such as 4% chlorhexidine wash, to reduce the spread of bacteria on the skin. An antibiotic lotion such as clindamycin may be recommended for affected skin.
- Antibiotic tablets: These may be prescribed for a prolonged time in order to try to help suppress further attacks. Tetracycline antibiotics such as lymecycline and doxycycline are often tried initially. The combination of clindamycin and rifampicin is another option; potential side effects include an upset stomach, orange tears and urine, and reduced effectiveness of the oral contraceptive pill. In HS, antibiotics may work by suppressing inflammation rather than by killing bacteria.
- Retinoids (vitamin A derived tablets) such as acitretin may help too, but are given with caution by specialists, so they are available only from dermatology clinics. Women who have taken acitretin should avoid pregnancy for three years afterwards and so this treatment is usually avoided in women of child-bearing age.
- For women who have flares of HS before each period, tablets known as anti-androgens can sometimes be useful. Anti-androgen treatment can be as part of a contraceptive pill.
- Tablets to alter the immune system: some tablets such as dapsone and ciclosporin may be considered to try to improve HS by dampening down the immune system. Benefits are balanced against potential side effects and blood test monitoring is needed.
- Immuno-suppressive injections: Injection treatments designed to suppress the immune system are used for HS that has not improved with other medical treatment. These ‘biologic’ treatments include adalimumab, injected under the skin, and infliximab, given as an intravenous infusion.
Persistent discharge or inflammation in the same site despite medical treatment can sometimes require surgery, either to remove small areas of repeated inflammation, or wider procedures to take away all the affected tissue. The wider procedures probably reduce the chance of HS coming back in the treated area, compared to smaller procedures, but healing times are generally longer.
Self Care (What can I do?)
The following measures may be beneficial:
- losing weight and stopping smoking (if relevant)
- washing with antiseptic soaps or bath additives
- avoiding tight clothing
- stress management
- consider joining a support group
This information is provided by the British Association of Dermatologists.
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