Hidradenitis suppurativa

What is hidradenitis suppurativa?

Hidradenitis suppurativa (HS) is a long-term, recurrent and painful inflammatory skin condition. It affects areas of skin where skin rubs together and where there are certain types of sweat glands, mainly the armpits, groin, inner thighs, genital area, buttocks, under the breasts and the tummy fold.

HS starts with blockage of hair follicles. The blocked follicles swell and burst under the skin, causing inflammation, painful lumps and abscesses. Over time, tunnels (sinus tracts) can form under the skin, and scarring can develop.

Who gets it?

HS affects about 1 in 100 people in the UK. Women, and people with darker skin tones, are affected more often. It is rare before puberty and usually begins in late teens or early adulthood.

What causes it?

The cause is not fully understood. The process is believed to begin when a hair follicle becomes plugged, which then triggers an exaggerated immune reaction. Hormones appear to play a part, and many women notice flares before periods. Skin bacteria that are normally harmless can get trapped and make the inflammation worse.

HS is strongly linked with smoking, and many people with HS smoke, although non-smokers are also affected. Being overweight increases the likelihood, but people of every body weight can have it. Friction from tight clothing and skin rubbing together can make it worse.

Poor hygiene does not cause HS, and it is not an infection.

Is it hereditary or contagious?

HS runs in families in about a third of people. It is not contagious and cannot be passed on to anyone else.

What does it look and feel like?

Early HS can look like blackheads, pus spots or tender red lumps that resemble boils or cysts. The lumps are often painful and may burst and leak pus or blood, which can have an unpleasant smell. In later stages, tunnels form under the skin that can leak repeatedly, and wounds may be slow to heal. Rope-like scarring can develop.

Pain can make it difficult to walk, sit, exercise or work, and drainage may need dressings. HS can have a significant impact on mood, relationships and quality of life, and depression and anxiety are common. These are important to discuss.

Associated conditions

HS is associated with acne, dissecting cellulitis of the scalp and pilonidal sinus. It is also associated with diabetes, high blood pressure and cholesterol, inflammatory arthritis, and bowel inflammation such as Crohn's disease. Tell your doctor if you notice ongoing diarrhoea, bleeding from the bowel, weight loss you cannot explain, or painful, swollen joints.

How is it diagnosed?

There is no specific test for HS. It is diagnosed from the history and examination, based on recurrent painful lumps in typical areas. HS is frequently mistaken for recurrent boils or infection, and many people wait years for a diagnosis. Recognising it early is important, because early management can help limit scarring.

What are the treatment options?

Dr Mounsey will assess the severity of your HS and agree a plan aimed at reducing flares, pain and scarring. Treatment starts with antiseptic washes and practical advice, including support with weight and stopping smoking, as these can make a real difference. Medical options include antibiotic creams, longer courses of antibiotic tablets such as tetracyclines or clindamycin with rifampicin, and hormonal treatments for some women. For moderate to severe HS, biologic injections such as adalimumab, secukinumab or bimekizumab may be suitable. Painful lumps can be injected with steroid, and surgery may be recommended for persistent tunnels, with referral arranged where needed.

What is the outlook?

There is no cure for HS. HS tends to last for years, though it may quieten down with time, and treatment can make flares less frequent and less severe. For most women HS stays the same or gets better in pregnancy, although a flare can follow the birth.

More information

British Association of Dermatologists patient leaflet: https://www.bad.org.uk/pils/hidradenitis-suppurativa

This page gives general information only and is not a substitute for a consultation. Everyone's skin is different, and what is right for you will depend on your own circumstances. If you are worried about a skin problem, please book an appointment with Dr Mounsey or speak to your GP. If you have a mole or skin lesion that is changing, bleeding or growing quickly, please seek medical advice promptly.