Hidradenitis Suppurativa: Everything to Know

Hidradenitis suppurativa is a chronic inflammatory skin condition that causes painful lumps under the skin. It is also called acne inversa or inversus. Hidradenitis suppurativa affects around 0.3% to 4% of the population worldwide. Lumps appear deep underneath the skin and typically occur in areas where skin touches skin, such as the armpits or inner thighs. The lumps can resemble acne cysts, sores, or boils.

Read on to learn more about hidradenitis suppurativa. This guide includes information about symptoms, treatments, causes, and more.

Doctors use the Hurley system to assess the severity of hidradenitis suppurativa. The stages of hidradenitis suppurativa are as follows:

• Hurley Stage I: You will have either a single abscess or individual abscesses without any tunneling or scarring.
• Hurley Stage II: You will have recurring abscesses with either one or more spaced out lesions. There will also be the formation of a sinus tract, which runs from the site of infection to the surface of the skin.
• Hurley Stage III: You will have multiple lesions with interconnecting sinus tracts and scarring.

The main symptom of hidradenitis suppurativa is a lump that looks like a pimple or a boil. This typically appears on parts of the body where skin touches skin. Examples of places on the body it can appear include:

• underneath or on the breast
• armpit
• waist or lower stomach
• genitals
• around the anus
• buttocks
• inner thighs

Following a breakout, you may find that the area can clear up for a while. Breakouts can recur in the same place, or they may appear in different areas of the body.

A breakout of hidradenitis suppurativa will typically develop as follows.

1. Skin is tender before the lump appears, and this can burn, feel itchy, or sweat.
2. You will notice an individual painful spot.
3. Lumps that look like acne or boils can grow and join together and fill up with fluid, turning into an abscess.
4. The abscess can break open, releasing blood and pus. This can have a foul smell.
5. You may notice blackhead-like spots, usually appearing in pairs, in the advanced stage of the condition.
6. Abscesses heal and reopen repeatedly, which causes sinus tracts and scarring.

Treatment can help prevent abscesses from continually healing and reopening.

Find out more about the signs and symptoms of hidradenitis suppurativa here.

Hidradenitis suppurativa treatment depends on the stage of the condition. Antibiotics may be the first line of treatment in the early stage of the condition.

Doctors use several classes of medications to treat hidradenitis suppurativa. These include:

• oral or topical antibiotics, which help decrease inflammation and prevent infection
• oral retinoids such as acitretin, which decrease inflammation and reduce skin cell turnover rate
• biologics such as adalimumab, which target the immune system to prevent inflammation and pus
• isotretinoin, which treats severe acne
• hormonal medication such as birth control pills, spironolactone, or finasteride
• metformin, which is a drug for diabetes that can help reduce inflammation
• corticosteroid injections, to reduce inflammation

For severe hidradenitis suppurativa that affects deeper layers of your skin, surgery may be necessary. One Australian study found that 39.5% of people with Hurley Stage II hidradenitis suppurativa have surgery, and this increases to around 54.3% with Hurley Stage III.

Your dermatologist may also recommend one or more procedures to help reduce the number of lumps you have or to reduce the severity of your symptoms.

Surgery and procedures for hidradenitis suppurativa include:

• Incision and drainage: If you have an abscess, incision and drainage can drain the pus from the lump and relieve pain.
• Laser hair reduction: If you have less hair on your skin, this may lessen the number of lumps you have. This procedure typically occurs once every 4–6 weeks.
• Deroofing: During a deroofing procedure, your dermatologist will remove the layer of skin that covers the top of the abscess or sinus tract. The wound can then heal on its own.
• Wide excision: A dermatologist will remove the lesion from the skin during wide excision. This results in a wide and open wound, which you will typically leave to heal on its own.
• Laser surgery: Laser surgery uses strong lasers to vaporize hidradenitis suppurativa. Recovery time for your skin following laser surgery is around 6 months.
• Botulinum toxin: Botulinum toxin is suitable for conditions that cause excess sweating. It can help reduce sweating and subsequent infection in people with hidradenitis suppurativa.

Your doctor or dermatologist may recommend procedures such as wide excision and laser surgery if medication has not been effective.

If you have wounds as a result of hidradenitis suppurativa or related surgery, it is important that you care for the wounds while they heal.

Your dermatologist will assess your wounds and advise on the best plan for treating them. Wound care may involve:

• changing dressings, sometimes several times per day
• applying a clean washcloth soaked in diluted vinegar to decrease odor
• using antiseptic washes to relieve pain and discomfort

Medical professionals do not know the exact cause of hidradenitis suppurativa. It happens when hair follicles become clogged with keratin, sweat, and bacteria. This clogging triggers abscess formation and scarring.

Contact your doctor or dermatologist if you experience any kind of lump that causes pain or discomfort, particularly if it does not go away or if it keeps coming back.

Not all medical professionals are aware of hidradenitis suppurativa. As there is an average of 7.2 years between the onset of the condition and diagnosis, it is important to contact your doctor as soon as possible.

Read our guide for advice on talking to your doctor about hidradenitis suppurativa here.

There is no specific test for diagnosing hidradenitis suppurativa. Misdiagnosis is often common in the early stages.

To diagnose the condition, your doctor will carry out a physical examination, and they may take a swab from the skin or pus.

Find out more about why doctors can misdiagnose hidradenitis suppurativa here.

While medical professionals do not know the exact cause of hidradenitis suppurativa, there are certain factors that appear to increase the likelihood of developing hidradenitis suppurativa.

Possible risk factors for hidradenitis suppurativa include:

• a family history of the condition
• smoking cigarettes, which occurs in 70–90% of people with hidradenitis suppurativa
• overweight or obesity
• psoriasis
• sex, with females being more likely to have the condition than males
• race, with African American and Hispanic American people at higher risk

When hidradenitis suppurativa becomes severe or persistent, complications can develop. These can include:

• secondary infections
• scarring
• an increased risk of squamous cell carcinoma skin cancer

Learn more about the complications of hidradenitis suppurativa here.

Below are some other frequently asked questions about hidradenitis suppurativa.

Hidradenitis suppurativa is not a sexually transmitted infection (STI). You cannot pass it to another person during sex.

Treatment is necessary for managing hidradenitis suppurativa and relieving symptoms. This can include a combination of medication and procedures.

Hidradenitis suppurativa is not contagious.

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Visit our hidradenitis suppurativa hub for more information and articles here.

Hidradenitis suppurativa is a condition wherein painful lumps appear beneath the skin. They can grow and interconnect, developing into pus filled abscesses.

There is currently no cure for hidradenitis suppurativa, but it is possible to manage the condition. Treatment for hidradenitis suppurativa includes medications and injections, as well as surgery for more severe cases.

Contact your doctor or dermatologist if you have concerns about hidradenitis suppurativa. They will be able to assess your condition in line with the Hurley system and advise on the best course of treatment.