Hidradenitis suppurativa (HS), also called acne inversa, is an inflammatory skin condition that causes painful bumps — typically in the armpits, groin, buttocks, and the underside of the breasts. In stage 3 HS, there are recurring nodules (pus-filled lumps) and abscesses, interconnected tunnels (or sinus tracts), and severe scarring across large areas of the body. Stage 3 HS is less common and, by some estimates, affects about 1 percent of people living with HS.

What Is Stage 3 Hidradenitis Suppurativa?

HS begins at the hair follicle, where inflammation causes painful discolored nodules, boils, or abscesses within the armpits, groin or genital area, thighs, and buttocks. HS may also sometimes affect the face, neck, area behind the ears, abdominal fold area, and skin under the breasts. HS is not contagious. It is not sexually transmitted nor caused by poor hygiene.

The severity and development of HS are classified by three stages using the Hurley staging system. (Stages are sometimes referred to using Roman numerals, e.g., stage II instead of stage 2.)

• Stage 1 involves one nodule or isolated abscess without sinus tract formation (narrow openings underneath the skin) or scarring.
• Stage 2 involves recurrent abscesses or nodules with widely separated lesions, sinus tract formation, and scarring
• Stage 3 involves multiple recurrent abscesses or nodules, interconnected draining sinus tracts, and severe scarring

In stage 3, new nodules and abscesses form as soon as older ones have healed, either in the same or new areas of the skin. Over time, this causes significant scarring, interconnected tunnel formation, and widespread inflammation.

What Causes HS?

Although the cause of HS remains unknown, certain risk factors are associated with its development. These risks include:

• Genetics — About 40 percent of individuals have a family member with HS
• Smoking tobacco
• Being overweight or obese
• Having other health conditions, such as severe acne, arthritis, diabetes, metabolic syndrome, and inflammatory bowel disease (IBD)

HS triggers include excessive sweat, heat, stress, fatigue, wearing tight clothing, and hormonal changes during the menstrual cycle in some women.

In the United States, Black people have a high prevalence among other races to develop HS, according to Mayo Clinic. Women are also more likely to develop HS compared to men.

Symptoms of Stage 3 Hidradenitis Suppurativa

Stage 3 HS lesions appear at new sites or reappear near or on the same spot as the initial lesion. HS lesions affect areas of the body with many lymph nodes and apocrine sweat glands (including armpits, groin, buttocks, and below the breasts). However, as HS progresses to stage 3, areas of the body where the skin repeatedly rubs together are affected, such as the nape of the neck, torso, waistband (or abdominal fold), perianal (around the anus), and thighs. In rare cases, HS lesions can also appear on the face.

Stage 3 HS lesions are large and inflamed boil-like lumps filled with foul-smelling pus. In stage 3 HS, narrow channels called sinus tracts form under the skin and break out on the surface, leaking pus and fluid. Multiple areas of HS lesions become interconnected under the skin by sinus tracts, leading to widespread inflammation.

Stage 3 HS lesions cause severe scar tissue formation and wounds that leak. Scar tissue can interfere with the lymphatic system and cause swelling in the arms, legs, or genitals. Some HS lesions may become infected with bacteria, causing an infection.

Stage 3 HS symptoms are more severe than those of stage 2 HS. Nodules and abscesses commonly reappear more than two times every six months. Although signs and symptoms of stage 3 HS may vary from person to person depending on the area of skin affected, the most common symptoms reported include:

• Ten or more inflammatory nodules (e.g., cysts)
• Multiple recurring painful pea-sized abscesses filled with pus
• Multiple interconnected sinus tracts that drain fluid
• Leaking bumps and sores, sometimes with a foul-smelling odor
• Extensive and deep scarring
• Severe discomfort, burning, or itching on the affected area of skin
• Swelling in the arms, legs, or genitals
• Anxiety or depression

Other Symptoms

One study found that people living with stage 3 HS experienced challenges during work or school activities. Severe scarring and chronic inflammation from stage 3 HS lesions can lead to:

• Restricted movement (specifically in the thighs or armpits)
• The development of an anal fistula (infected tunnel between the skin and the anus)
• Anal stenosis (narrowing of the anal canal)
• Urethral stricture (narrowing of the urethra, or tube that carries urine out of the body)

Stage 3 HS can also lead to severe infections on affected areas of the skin.

Additionally, studies have found that the negative stigma associated with HS has a substantial emotional impact on individuals and may increase the risk of depression, social isolation, and poor self-esteem. About 42.9 percent of people living with HS are diagnosed with depression.

Treatments of Stage 3 Hidradenitis Suppurativa

There is no cure for HS, but many treatments available can help you manage your symptoms. Dermatologists recommend treatments based on the stage of HS. Other factors, including the severity of symptoms, the number of lesions, and the person’s general health and medical history, are also considered.

Stage 3 HS is treated with a combination of medications and therapies, including:

• Oral retinoids, like acitretin and isotretinoin
• Hormonal therapy, such as cyproterone acetate, birth control pills, finasteride, or spironolactone
• Biologic medicines, such as Humira (adalimumab), which may be prescribed off-label
• Anti-inflammatory drugs, such as metformin
• Botulinum toxin (Botox) to treat excessive sweating
• Nonsteroidal anti-inflammatory drugs (NSAIDs), including ibuprofen, to treat both pain and inflammation

Surgical treatments are needed if multiple medical therapies have failed. They include:

• Incision and drainage, to drain the abscess and relieve pain
• Deroofing, to remove the area of skin with abscess or sinus tract
• Wide excision, to remove lesion or tunnel wound

Skin Care Tips

Doctors may sometimes recommend topical antiseptic washes, such as 4 percent chlorhexidine or benzoyl peroxide, to keep the skin area clean and reduce the risk of a bacterial infection.

Other ways to treat stage 3 HS lesions at home include:

• Applying a warm compress on the area of the skin for a few minutes
• Wearing loose-fitted undergarments and clothing to minimize friction
• Using antibacterial soap on the site of the skin
• Avoiding skin care products that irritate the skin
• Avoid shaving affected areas, such as the underarms, groin, genital area, or buttocks
• Minimizing heat exposure and sweating
• Keeping the site of skin dry and cool

Managing Stage 3 Hidradenitis Suppurativa

Living with stage 3 HS is challenging. This inflammatory skin disease has a profound effect on a person’s quality of life, specifically on their mental and social health. However, some lifestyle changes may help manage or relieve symptoms for some individuals.

Quitting Smoking

The link between smoking and HS has been well studied. Smoking tobacco can increase inflammation throughout the body, worsening HS symptoms. Studies have found that most people with HS are active smokers and have higher disease severity. By quitting smoking, you may reduce your risk of HS flare-ups.

Read more about hidradenitis suppurativa and smoking.

Adjusting Your Diet

Certain foods and stress can trigger a flare-up in some people. The Mayo Clinic recommends that people with HS eliminate dairy products, reduce sugar, and avoid brewer’s yeast. Changing your diet may also be a helpful and healthy way to lose weight.

Read more about diet and hidradenitis suppurativa.

Losing Weight

There is a strong association between increasing body mass index (BMI) and the increasing severity of HS. Weight loss or managing a healthy weight may reduce your risk of recurrent lesions (or flare-ups) or worsening the progression of HS.

Talk With Others Who Understand

Living with HS can be difficult, but you are not alone. On myHSteam, the social network for people with hidradenitis suppurativa and their loved ones, more than 23,500 members come together to ask questions, give advice, and share their experiences with others who understand life with hidradenitis suppurativa.

Do you have stage 3 hidradenitis suppurativa? What advice do you have for others? Share your thoughts in the comments below or by posting on myHSteam.