One biologic, adalimumab, is currently approved to treat hidradenitis suppurativa. Adalimumab works by targeting a specific inflammation pathway involved in the condition.

Hidradenitis suppurativa (HS) is an inflammatory condition where painful nodules and abscesses develop on your skin. If left untreated, HS can lead to scarring and tunnels under your skin, called sinus tracts, that can drain pus.

There’s no cure for HS. Treatment can include medications, lifestyle changes, and potentially surgery.

One type of medication that may be used for HS is called a biologic. Biologics are scientifically engineered drugs that target certain molecules in your body, such as those that cause inflammation.

This article takes a closer look at how biologics are used to treat HS.

Fast facts about hidradenitis suppurativa

  • The most common sites for HS lesions are areas where skin touches skin, such as your armpits, groin, and under the breasts.
  • It’s been estimated that HS affects between 0.03% and 4% of the global population.
  • What exactly causes HS is still unknown.
  • HS typically develops between puberty and age 40. It’s rare for HS to begin before puberty.
  • People who are assigned female at birth are three times more likely to develop HS. The reason for this is unknown, but hormones may play a role.
  • In the United States, individuals who are African American or biracial are more likely to have HS and are more likely to have severe HS. The reason for this isn’t known.
  • Other risk factors for HS include:
    • having a family history of HS

Biologic drugs come from a living source. Examples of biologics are monoclonal antibodies and vaccines. To understand how they work for HS, it’s first important to go over what’s known about what’s going on in the skin of people with HS.

HS starts when a hair follicle becomes clogged with keratin, a protein found in skin, nails, and hair. Sweat and bacteria also accumulate in the hair follicle. As this happens, immune cells are attracted to the area, raising inflammation.

Eventually the hair follicle bursts, releasing its contents into the skin where it can affect other hair follicles. This leads to a further boost in inflammation and formation of additional lesions.

Biologics for HS work by targeting the inflammation associated with the condition. Unlike many other anti-inflammatory drugs, they target very specific inflammation pathways.

The only biologic that’s approved by the Food and Drug Administration (FDA) to treat HS is adalimumab (Humira). Adalimumab inhibits the activity of TNF-alpha, a small protein involved in the inflammation associated with HS.

Adalimumab is used for individuals ages 12 and over with moderate to severe HS. Many times, it’s prescribed when other medications haven’t been effective at managing HS.

You take adalimumab as an injection under your skin. To start, you’ll typically receive an initial dose and a second dose 2 weeks later. Going forward, you’ll take adalimumab once each week.

It’s important to be patient when you start on adalimumab. This is because it may take several weeks before you see an improvement with adalimumab.

Results of two clinical trials found that after 3 months, 41.8% and 58.9% of people on adalimumab had at least a 50% reduction in nodules and abscesses. This is compared with 26% and 27.6% of people in the placebo groups, respectively.

The effectiveness of adalimumab may increase with time. A small 2018 study of 19 people with HS found that the percentage of people having a clinical response with adalimumab increased from 42.1% at 3 months to 63.2% at 6 months.

Like any medication, adalimumab can have side effects. According to the prescribing information, the most common side effects include:

Rarer, but more serious side effects can include:

Researchers are looking into the use of other biologics for HS. One example is infliximab (Remicade), which is approved to treat conditions such as:

A 2022 review of 19 studies of infliximab for HS found that the pooled response rate was 83%. Researchers noted that while infliximab appears to be effective for HS, it needs to be tested in larger clinical trials.

Other biologics and immune-modulating treatments have also been investigated with varying results.

Other treatment therapies being researched for HS

Some examples of other medications and therapies that are currently being tested for HS in clinical trials are:

To learn more about clinical trials for HS, visit ClinicalTrials.gov.

Biologics for HS target and inhibit specific inflammation pathways. Currently, the only biologic that’s approved by the FDA for HS is adalimumab (Humira). Other new treatments for HS, including biologics, are being tested in clinical trials.

Adalimumab is typically used in people with moderate to severe HS for whom other treatments haven’t been effective. It has a variety of side effects, so be sure to discuss these with a doctor before starting on adalimumab.