If you live with hidradenitis suppurativa (HS, or acne inversa), it’s important to understand how severe your condition is. Knowing the stage of your HS can help your health care team determine the best treatment plan for you.

One common way to measure the severity of your HS is by using the Hurley stages. If your dermatology team ever mentions Hurley stages, here’s what you need to know.

What Is Hidradenitis Suppurativa?

HS is a long-term skin condition that happens when hair follicles in areas where skin rubs together — like the armpits, groin, buttocks, or under the breasts — become inflamed. This leads to painful bumps under the skin called nodules or lesions. Over time, these can turn into abscesses (pockets of pus) and tunnels under the skin, called sinus tracts.

Symptoms of HS may include:

• Painful lumps under the skin
• Skin discoloration
• Blackheads (often in pairs)
• Nodules that may burst and leak foul-smelling pus
• Sinus tracts that can drain pus or blood

What Are the Hurley Stages of Hidradenitis Suppurativa?

Once you are diagnosed with HS, your dermatologist may use the Hurley staging system to classify the severity of your condition. The Hurley staging system, developed by a dermatologist in 1989, classifies HS symptoms into three distinct stages.

Some people with mild HS never progress to more advanced stages. However, for others, HS symptoms can worsen significantly if not treated. Early diagnosis and treatment can help prevent the condition from becoming worse over time.

The Hurley stages are specifically designed to help determine what type of treatment you need for HS. You may have different stages of HS in various parts of your body. This could require different treatments for each area.

Hurley Stage 1 (Mild)

Stage 1 HS (Hurley stage 1) involves one lesion or isolated abscesses without sinus tracts under the skin between the nodules. There is no scarring at this stage. HS often starts as small, painful, pea-sized bumps that are sometimes mistaken for acne, boils, or ingrown hairs.

If you look at pictures of HS stage 1 symptoms, you’ll often see small discolored blotches. Though the bumps may not look severe, they can still be painful and uncomfortable.

Research shows that 68 percent of people with HS are in stage 1, although estimates vary. This stage is the most easily treated and often responds well to oral or topical medications. Your health care provider may refer to this as “medical therapy,” because surgery is not required.

Hurley Stage 2 (Moderate)

Stage 2 is marked by recurring sores and some scarring. You may also see a few tunnels between the individual bumps, but not many. The bumps are typically spread farther apart at this stage.

Stage 2 accounts for around 28 percent of people with HS. As in stage 1, oral or topical medications can be used for treating stage 2 HS. Your doctor might also recommend biologic drugs. If medications aren’t effective, surgical procedures may be needed. These procedures are usually local. This means they focus on one particular affected area rather than multiple areas.

What Does Stage 2 Hidradenitis Suppurativa Look Like?

Pictures of stage 2 HS (Hurley stage 2) usually show multiple discolored bumps or blotches. Some of them may be broken open or scabbed over. You might see scarring from previous nodules that have drained and healed.

Additionally, you might also see lines under the skin. connecting some of the nodules. These are the tunnels that have formed between them.

Hurley Stage 3 (Severe)

Stage 3 HS (Hurley stage 3) is the most severe form of HS. It involves multiple sores across an entire area of the body, with interconnected tunnels under the skin, scarring, and sometimes foul-smelling pus. At this stage, nearly all of the nodules in a particular location (such as under an armpit) become connected.

According to some estimates, stage 3 accounts for only a small percentage of HS cases. About 4 percent of people with HS are classified as stage 3.

Stage 3 HS can be treated with oral retinoids, immunosuppressive medications, biologics, and surgery. Your doctor may also talk to you about surgery.

What Does Stage 3 of Hidradenitis Suppurativa Look Like?

Pictures of stage 3 HS usually show lots of skin discoloration and swelling. You may be able to see some individual nodules, but the rest can look like one large area where the nodules have merged. You may notice yellow areas under the skin where pus has built up. There might be individual nodules around the main area, as well as scars from previous nodules that have healed.

The Hurley System vs. the Sartorius Score

In addition to the Hurley staging system, some doctors use a more detailed system called the Sartorius score to assess treatment outcomes. A Sartorius score takes into account the parts of the body affected, the number and type of lesions, the distance between lesions, and the condition of the skin between the lesions. The Sartorius score is often used in research settings rather than in routine clinical practice.

How Quickly Does Hidradenitis Suppurativa Progress?

The progression of HS varies from person to person. Some people develop severe HS relatively quickly, while others have a slow progression over many years. By managing your symptoms, you can often stop new nodules from forming and help keep existing ones from getting worse.

How To Stop Hidradenitis Suppurativa From Progressing?

The exact cause of HS is still unknown. It might be connected to factors you cannot control, such as hormones, or genes you inherited from your parents. According to Mayo Clinic, other factors, like having excess weight or smoking cigarettes, may contribute to the development of this skin condition. This makes it difficult to address the problem at its source.

Although you can’t always address the underlying causes, there are various treatments available to manage HS and its progression. These treatments range from antibiotics and topical steroids to biologic medications, retinoids, and several different kinds of surgery. It’s important to work closely with your dermatologist to find the treatment option that works best for you.

Find Your Team

On myHSteam, the social network for people with hidradenitis suppurativa and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with hidradenitis suppurativa.

Have you discussed the Hurley staging system with your dermatologist? If your HS has gotten worse over time, how has your treatment plan changed? Share your experience in the comments below, or start a conversation by posting on your Activities page.