Hidradenitis suppurativa (HS) and psoriasis are two chronic, inflammatory skin diseases. Hidradenitis suppurativa generally affects the armpits, under the breasts, the groin, and the buttocks. Psoriasis affects the skin, nails, and joints and is typically characterized by scaly patches of skin. There is overlap in symptoms and risk factors for hidradenitis suppurativa and psoriasis. A dermatologist (a doctor who specializes in dermatology) treats both of these skin diseases. Read on to discover how these two conditions are connected.

Risk of Developing Hidradenitis Suppurativa

According to some research, hidradenitis suppurativa occurs in about 6 in 100,000 people. HS most commonly affects women in their 20s, according to a population-based study in Frontiers in Immunology. Hidradenitis suppurativa usually starts right after puberty.

Psoriasis is a very common skin disease, affecting more than 8 million Americans. Two percent to 3 percent of the world’s population has psoriasis, according to the National Psoriasis Foundation.

In a review of several recent studies, researchers found that people with hidradenitis suppurativa had a more than 2.6-fold higher risk of having psoriasis than people without hidradenitis suppurativa. The researchers did not determine that one condition causes the other. Instead they concluded that the conditions coexist. In the majority of cases, psoriasis comes before hidradenitis suppurativa.

Common Risk Factors

HS and psoriasis share some common risk factors, including smoking and obesity. Both conditions are also associated with specific inflammatory proteins (cytokines) in the body.

Related Health Conditions

Both conditions are also associated with some of the same comorbidities. These include:

• Metabolic syndrome
• Diabetes
• Inflammatory bowel disease (IBD)
• Spondyloarthritis

Symptoms of Hidradenitis Suppurativa and Psoriasis

Hidradenitis suppurativa and psoriasis are both inflammatory conditions that can negatively affect a person’s quality of life. There are some similarities and differences between the two conditions.

Hidradenitis Suppurativa

According to the American Academy of Dermatology, the first signs of hidradenitis suppurativa are recurring skin breakouts that look like pimples or boils. Individual breakouts often grow and clump together, forming painful abscesses that can break open. The repetitive reopening and healing can permanently scar the skin and cause sinus tracts — tunnels that form under the skin.

HS symptoms can cause serious pain and even restrict movement due to scarring.

Psoriasis

Broad symptoms of psoriasis include:

• Patchy, scaly rashes
• Itching, burning, and soreness
• Rashes that flare up and then subside

When psoriatic rashes occur in the armpit or groin area, psoriasis symptoms may be confused with hidradenitis suppurativa.

There are two subtypes of psoriasis that have symptoms most similar to hidradenitis suppurativa: inverse psoriasis (also called flexural psoriasis) and pustular psoriasis. Inverse psoriasis affects areas where the skin folds, including under the arms and around the genitals. In pustular psoriasis, skin develops pus-filled bumps. However, localized pustular psoriasis typically affects only the hands and feet.

Inflammation in Hidradenitis Suppurativa and Psoriasis

In both hidradenitis suppurativa and psoriasis, inflammation is responsible for symptoms. Researchers are working to determine whether the inflammatory pathways are the same in both. Specific inflammatory markers, like interleukin (IL)-17 and IL-23, appear to be especially elevated in both conditions. Biologic therapies, like tumor necrosis factor (TNF)-alpha inhibitors and IL-17 inhibitors, are used to treat both conditions.

Correlation or Causation?

There are only a couple of case studies that suggest hidradenitis suppurativa causes psoriasis or that psoriasis causes hidradenitis suppurativa. More epidemiology studies are needed. Right now, scientists think that the two conditions are only correlated with each other, not caused by each other. Given that there are common comorbidities with both diseases, this makes it more complicated when comparing their correlation or causation.

In the large population-based study in Frontiers in Immunology, researchers found that most people who had both diseases were young, obese smokers, as compared with people who had only psoriasis. The authors think this points toward a common inflammatory pathway.

Treatment Options

A dermatologist treats psoriasis and hidradenitis suppurativa with care. Depending on any comorbidities and the type of psoriasis you have, you may also visit a rheumatologist (a doctor who specializes in inflammatory diseases).

Treatment for Hidradenitis Suppurativa

Some of the common treatment approaches for hidradenitis suppurativa include medication and surgery. Common medications that a dermatologist may recommend are:

• Antibiotics
• Steroid injections
• Hormonal therapy
• Biologics
• Retinoids
• Pain medicine

Surgical procedures are sometimes used to treat hidradenitis suppurativa. Many of these procedures can be performed in your dermatologist’s office.

Treatment for Psoriasis

Treatment for psoriasis has some of the same recommended treatments, like retinoids, steroids, and biologics. Some other therapies that are more specific to psoriasis include:

• Vitamin D analogs
• Calcineurin inhibitors
• Light therapy
• Methotrexate
• Cyclosporine

Unlike HS, surgery is not used to treat psoriasis.

Hidradenitis Suppurativa Facts

If you are someone with psoriasis and have recently developed hidradenitis suppurativa, there are common misconceptions that ought to be cleared up. Here are some key facts to know about HS.

• HS is not contagious. It cannot be passed through sexual contact or any other physical contact.
• HS is not caused by poor hygiene. Even though the painful bumps are typically in the armpits and groin region, that is because these are the areas with lots of sweat glands and rubbing skin.
• Higher body weight does not cause HS. While having body weight can be a risk factor, people of all different types can develop hidradenitis suppurativa.

People with hidradenitis suppurativa may think that no one would understand them. It is important for them to know that there are many others with the disease and that talking with family, friends, and doctors can be extremely valuable. People with hidradenitis suppurativa should not feel embarrassed, and they should also know that their condition is not their fault.

Talk With Others Who Understand

MyPsoriasisTeam is the social network for people with psoriasis and their loved ones. On MyPsoriasisTeam, more than 125,000 members come together to ask questions, give advice, and share their stories with others who understand life with psoriasis.

Are you a caregiver of a child or teen with psoriasis and wonder about the link between psoriasis and hidradenitis suppurativa? Share your experience in the comments below, or start a conversation by posting on your Activities page.