What is hidradenitis suppurativa?
Hidradenitis suppurativa (HS) is a skin condition that affects 1-4% of people and occurs in the vulva, groins, buttock, and under the arms and breasts. These areas contain apocrine sweat glands, but these glands are not involved in the disease. HS is caused by issues with hair follicles, which tend to become blocked, inflamed, and full of fluid and old skin cells. These look like boils or large pimples. The hair follicles have weak walls that easily break open, spilling inflamed pus-like material into the surrounding skin. This leads to the formation of tunnels (sinuses) under the skin that may have multiple entry and exit points. A cycle of inflammation and drainage occurs in areas of boils and sinus tracts. This process feels and looks like bacterial infection, but it is not. Instead, the swelling, pain, and pus-like drainage are the result of inflammation.
What problems does HS cause?
HS is not contagious or sexually transmitted. It is not related to how often people shower or bathe. Some people with HS have mild disease with an occasional boil that resolves itself. Others have severe disease and have large areas covered in boils, sinus tracts, and scars with constant pain and drainage. No one knows why it affects individuals so differently.
Multiple factors contribute to a person developing HS – their genetic makeup, use of tobacco, friction in the affected areas, and hormonal influences. It is usually worse during the ages of 16 to 50 and improves after menopause. In some people it gets better during pregnancy.
HS is an uncommon and misunderstood disease. Many people have HS for years before someone identifies the diagnosis. Bacterial swabs are usually negative, but patients are still told they have recurrent infections. Sometimes they are told they have a hormone imbalance, but in fact most people with HS have normal hormone levels. Some patients receive multiple unhelpful treatments, like short courses of antibiotics, repeated lancing of boils, or surgeries to cut out lumps and sew the skin back together. All of this can lead to depression, anxiety, and a sense of frustration with the medical system.
Treatment of hidradenitis suppurativa
HS is a chronic disease. This means that it can be controlled but not cured. Your GP is important in the long-term management of HS and may refer you to a dermatologist or vulval specialist. A combination of strategies is often necessary to keep the disease under control. These include lifestyle changes, topicals, tablets, injections, and/or surgical procedures.
- Reducing irritation to the vulval skin (see Vulval care advice)
- Resisting the urge to pick at or squeeze boils
- Avoiding excess heat, moisture, friction, and sweat in affected areas
- Achieving and maintaining a healthy weight
- Working to quit tobacco
- Taking a zinc supplement (zinc gluconate 90mg daily) may help some people
- People with a low vitamin D level may improve with vitamin D supplements
- Washing with phisohex or chlorhexadine
- Clindamycin 1% in aqueous cream daily may be helpful short-term in mild disease
- Resorcinol 15% in emollient base applied twice daily to flared areas
- Doxycycline or minocycline are antibiotics that have an anti-inflammatory effect. They are also used for acne. The usual dose is 50-100mg daily.
- The oral contraceptive pill (OCP) helps to reduce blood levels of androgens, so often improves HS. Testosterone is an androgen – these are hormones that make hairs thicker and hair follicles more likely to become blocked. Pills containing drospirenone or cyproterone might have more of an impact, but any OCP will reduce the level of active androgens.
- Spironolactone increases production of urine and lowers blood pressure. It also has an anti-androgen effect that helps with HS management.
- There are other anti-androgen medications that are used less often.
- A small amount of corticosteroid may be injected into boils to make them heal faster.
- In cases of severe disease, some dermatologists prescribe biologic medications that block inflammatory chemicals produced by the immune system. Some patients find these helpful, while others report no difference.
- Once a sinus tract is formed, it will not go away on its own. A minor procedure called ‘deroofing’ can be done with a local anaesthetic or in the operating theatre. The doctor opens the sinus tract, cleans out the inflammatory debris, stops any bleeding, and allows it to heal from the inside out. The skin is NOT stitched together because this could encourage the sinus tract to re-form. When it finishes healing, there is a small scar that does not have hair follicles, so this area tends to not be a problem anymore.
- In extremely severe cases, major surgery is may be required to remove most of the vulva or buttock, with a need for skin grafting or large skin flaps to close the wound.
What does the future hold?
HS gets better and worse at different stages of life, but usually doesn’t go away. Since it can be so distressing, people often need some form of treatment for most of their life. Patients and their doctors can usually find a combination of strategies that keep this disease as inactive as possible and this greatly improve quality of life.