Many classes of drugs have been developed to help manage and treat hidradenitis suppurativa (HS), including antibiotics, topicals, retinoids, and more. These treatment options are prescribed to manage the lesions, bumps, and scarring on the skin that HS can cause.

Biologic drugs are made from living organisms. These drugs treat severe HS by selectively targeting the immune system, which helps to control inflammation.

In this article, we discuss the use of biologics for the treatment of HS, including existing and future treatment options.

What Is Hidradenitis Suppurativa?

HS, also known as acne inversa, is an inflammatory skin disease that causes small, painful bumps to form under the skin. These form in areas where the skin rubs against itself, such as the groin, armpits, breasts, and buttocks. People with HS can develop pus-filled abscesses, sinus tracts (tunnels under the skin), and scarring.

HS is thought to be caused by blocked hair follicles, in addition to chronic inflammation. However, the exact cause of the condition is unknown. Many people with HS have increased levels of inflammatory markers known as cytokines, which can be managed using biologic treatment.

How Do Biologics Work?

To understand how biologics are used to treat HS, it is important to know more about the immune system, inflammation, and a class of biologics known as monoclonal antibodies.

Antibodies are proteins that form a vital part of the immune system. They are produced by specialized immune cells, known as B cells, to fight bacterial or viral infections. The human body can make almost 100 billion different types of B cells, and each type of B cell produces only one type of antibody. Each antibody is a protein that recognizes and interacts with a specific target.

B cells can also be genetically altered in a lab to produce specific antibodies that attach to a target protein. These are known as monoclonal antibodies because they are produced from one type of B cell.

Every antibody made by that B cell will have the same properties. Researchers have designed monoclonal antibodies to target specific proteins on the outside of immune cells, cancer cells, and other abnormal cells associated with the disease.

Biologics for Hidradenitis Suppurativa

There are several categories of biologics with different targets. Currently, adalimumab (Humira) and secukinumab (Cosentyx) are the only biologics approved by the U.S. Food and Drug Administration (FDA) to treat HS. Adalimumab binds to tumor necrosis factor-alpha (TNF-alpha), which is involved in inflammation. Secukinumab blocks interleukin (IL)-17A, a chemical messenger that’s involved in inflammation in many chronic diseases.

Two other biologics — ustekinumab (Stelara) and infliximab (Remicade) — have not been approved by the FDA for use in HS. However, they can be prescribed off-label to treat cases that have not responded well to other treatments. Ustekinumab works by blocking inflammation caused by the cytokines IL-12 and IL-23. Infliximab is also a TNF-alpha blocker and binds directly to the protein to dampen inflammation.

When Is the Right Time To Consider Biologic Treatment?

Biologics are typically used to treat moderate to severe HS or when other treatments have failed to work. Your dermatologist will discuss your treatment options and evaluate which may work best for you. Biologics may also be a good option if you’re being treated for another inflammatory disease.

What To Expect When Starting Biologics

All biologics are given as injections or infusions — either subcutaneous (under the skin), intramuscular (into muscle), or as intravenous (into a vein) infusions. Biologics cannot be taken by mouth because they are broken down in the stomach and intestines before being absorbed into the bloodstream.

Before starting biologic therapy, you may undergo screening tests to make sure you are not at risk from any underlying conditions. Screening may include tests for tuberculosis and hepatitis B and C. You may be monitored for these or other conditions during treatment to make sure you are not at risk for developing any complications.

Side Effects of Biologics

In most cases, the benefits of using approved drugs to treat a condition outweigh the possible side effects you may experience. The overall goal of treatment is to improve your quality of life. If you notice side effects, talk to your doctor about how to manage them and ask whether they may fade over time.

Common side effects associated with biologic drugs include:

• Headaches
• Discoloration, pain, swelling, and itching at the injection site
• Nausea
• Increased risk for infections because the drugs work by suppressing the immune system
• Injection or infusion reactions, which are similar to allergic reactions (rash, pain, swelling, flushing, headache, etc.)

Always listen to your body. If you experience any of these new symptoms after using biologic drugs, contact your doctor right away:

• Painful rash or sores
• Fever, sweating, or chills
• Chest pain
• Dizziness
• Shortness of breath
• Cough
• Bleeding or bruising easily
• Vision problems
• Diarrhea or stomach pain

These are all signs of an infection or a more serious condition that should be addressed immediately.

What Is Being Researched?

Several clinical trials are investigating new or available biologics for treating HS. These trials are promising for the development of new treatments, or the repurposing of already-existing drugs.

Biologics being studied to treat moderate to severe HS include:

• Brodalumab — Inhibits (blocks) the function of IL-17 receptor A
• Bimekizumab — Inhibits the function of IL-17A and IL-17F
• Spesolimab — Inhibits IL-36 receptor and is currently being studied for the treatment of Crohn’s disease, psoriasis, and other autoimmune diseases

This work means that there may be additional HS treatments that become available in the future to people living with HS.

Talk With Others Who Understand

On myHSteam, more than 41,000 members from around the world come together to ask questions, offer support and advice, and share their stories with others who understand life with hidradenitis suppurativa.

Are you taking any biologic medications to treat your HS? Share your experience in the comments below, or start a conversation by posting on your Activities page.