Hidradenitis suppurativa (HS) is a complex skin condition. It involves inflammation, clogged hair follicles, and sometimes bacterial infections. It’s not contagious, and it’s not caused by poor hygiene.

Treatment can be tricky. Some people try topical creams, oral antibiotics, hormone therapies, or biologics. But not every medication works for every person. One treatment that sometimes helps is Bactrim, a prescription antibiotic that combines two drugs: trimethoprim and sulfamethoxazole (TMP/SMX).

So how does TMP/SMX fit into HS treatment? Is it a reliable option for people with HS? And more specifically, does it work on the painful boils this condition is known for?

This article will walk you through what TMP/SMX is, how it’s used for HS, what the research says, and what to expect if your doctor prescribes it.

What Is Bactrim?

TMP/SMX is an oral antibiotic made up of two active ingredients: sulfamethoxazole and trimethoprim. These two drugs work together to stop bacteria from growing. It’s commonly used for infections like urinary tract infections (UTIs), bronchitis, traveler’s diarrhea, and certain types of pneumonia.

TMP/SMX is also used to treat skin infections caused by Staphylococcus aureus (S. aureus, also called staph). Staph infections can also cause boils. Sometimes HS is confused with boils caused by a staph infection. In the case of a staph infection, TMP/SMX works by stopping the growth of bacteria that cause these infections.

TMP/SMX is one of many oral antibiotics that dermatologists may prescribe for HS.

How Do Oral Antibiotics Help in Hidradenitis Suppurativa?

Unlike boils caused by S. aureus, HS isn’t caused by a bacterial infection. In the case of HS, antibiotics like TMP/SMX are used to help control inflammation, as well as bacteria on the skin that may be contributing to the inflammation without causing a true infection. Oral antibiotics can be used to treat mild to severe HS, depending on the medication. They can treat an acute flare-up, or they can be used as ongoing treatment to control your HS. Dermatologists will typically prescribe oral antibiotics for a few months at a time if they’re being used for longer-term management.

TMP/SMX is not usually the first antibiotic a dermatologist prescribes. However, it can be helpful for people who don’t respond to first-line antibiotics. Your dermatologist may suggest different antibiotic classes depending on how you respond.

If an HS lesion or abscess becomes infected, your doctor might also prescribe oral antibiotics. It’s important to seek care right away if a wound becomes infected.

What Does the Research Say About Bactrim for Hidradenitis Suppurativa?

There isn’t a lot of large-scale research specifically on TMP/SMX for HS, but some smaller reports and case studies suggest that it can help certain people.

In some cases, people with moderate to severe HS experienced improvement with TMP/SMX after other antibiotics failed. Other research explains that while TMP/SMX isn’t the most common first-line therapy, it has reportedly been used in some people with HS successfully, although there is not a lot of research to support its use.

It’s important to understand that most data comes from case reports or physician experience rather than randomized controlled trials, which are the gold standard for research.

When Is Bactrim Usually Prescribed for Hidradenitis Suppurativa?

Doctors might prescribe TMP/SMX for HS when:

• Other antibiotics like clindamycin or doxycycline haven’t worked
• A person is allergic to other more common HS antibiotics

In these situations, TMP/SMX may be part of a larger treatment plan. Managing HS often takes a combination of treatments, such as topical treatments, hormonal therapy, nonantibiotic oral treatments, or biologics. Depending on how advanced the HR is, surgery might also be included in the treatment plan. Proper wound care and skin care are also important.

As always, treatment for HS should be guided by a healthcare provider who understands the full picture.

What Are the Risks and Side Effects of Bactrim?

Like all medications, TMP/SMX can have side effects. Some are mild, and some can be more serious. Common side effects include:

• Nausea
• Vomiting
• Loss of appetite
• Skin rash
• Increased sensitivity to sunlight

Rare but serious side effects may include:

• Severe skin reactions (like Stevens-Johnson syndrome)
• Liver damage
• Low blood counts
• Allergic reactions

TMP/SMX is also not safe to use if you’re pregnant.

It’s important to let your doctor know if you experience any unusual symptoms while taking TMP/SMX. It can also interact with other medications, so your doctor will need to know about everything else you’re taking.

If you’re on TMP/SMX for more than a few days, you may be asked to have blood work done to check on your kidney function or blood cell counts, especially if you take other medications or have chronic conditions.

What Do myHSteam Members Say About Bactrim?

Several myHSteam members have been prescribed TMP/SMX. They’ve reported mixed results.

Some members have found relief: “They prescribed me some Bactrim. The flare seems to be going dormant instead of popping, but the pain is gone,” said one member.

Unfortunately, several members experience stomach problems or allergic reactions to TMP/SMX. One member wrote, “I’m also allergic to Bactrim.”

Another shared, “Bactrim upsets my stomach very badly.”

Talk With Others Who Understand

On myHSteam, people share their experiences with hidradenitis suppurativa, get advice, and find support from others who understand.

Have you been prescribed Bactrim for HS? Let others know in the comments below.