“Boil” is not a diagnosis. It is a word patients use for a painful lump that came up, hurt, and either drained or had to be opened. Underneath that one word sit at least four different problems with four different answers, and the reason people keep getting them is usually that nobody has said which one they have.

So the useful question is not what to put on it. It is where they keep happening.

Location does most of the diagnostic work

A furuncle is an infected hair follicle. It can turn up anywhere hair grows, it is usually staph, and a person who gets one is not necessarily a person who will get another.

Hidradenitis suppurativa lives in specific places. Armpits, groin, under the breasts, inner thighs, buttocks, around the anus. The same sites, over and over, often on both sides.

A pilonidal sinus sits in the cleft at the top of the buttocks and essentially nowhere else.

An inflamed epidermoid cyst comes back in exactly the same spot every time, because the sac is still there.

Four sites, four answers. If your lumps keep appearing in your armpits and groin, the working diagnosis is not recurrent boils.

The one that gets missed for years

Hidradenitis suppurativa is the diagnosis I most want people to know the name of, because the delay in getting it is measured in years rather than visits, and misdiagnosis is one of the biggest drivers of that delay (1).

What separates it from recurrent furuncles:

The same locations, repeatedly. Tunnels under the skin connecting one lesion to the next, which patients often describe as the drainage coming out somewhere other than where it went in. Rope-like scarring that builds up over years. Blackheads appearing in pairs, which is a small finding and quite specific. A family history, which is present often enough to be worth asking about.

Cultures from HS lesions frequently grow something, which is how it keeps getting called an infection. It is an inflammatory disease of the follicle, and antibiotics in it are working as anti-inflammatories more than as antimicrobials.

If you have been given six courses of antibiotics for boils in the same two places, you probably have HS and nobody has said so.

What actually treats an abscess

Drainage. Not antibiotics.

The IDSA guideline on skin and soft tissue infection puts incision and drainage as the treatment for a drainable abscess, with antibiotics as an adjunct in defined situations rather than a substitute (2). An abscess that is not opened does not resolve because someone took cephalexin.

This is why, practising by video, my rule is that a suspected abscess goes out to be drained rather than getting a prescription from me. I am firmer about that than some colleagues are, and I have not regretted it. A camera cannot tell me whether something is fluctuant, and a prescription that delays drainage by four days makes the eventual procedure bigger.

Why they keep coming back

For genuine recurrent furunculosis, the usual driver is staph colonization. The organism lives in the nose, the axillae, the groin, and it seeds new follicles.

Decolonization is the standard answer: intranasal mupirocin, chlorhexidine washes, attention to towels and razors. What is worth knowing is that treating the whole household beats treating the individual. Fritz and colleagues randomized exactly that comparison in children with community-associated staph infection and found household-wide decolonization more effective at eradication than treating the index patient alone (3).

That matters practically, because the patient who keeps recurring is often the one person in a house of four getting treated.

The part that belongs to my day job

Obesity, smoking and diabetes all sit behind recurrent skin infection, and they sit behind HS particularly hard.

Friction and skin folds are part of it, and plenty else is going on besides. Higher glucose impairs neutrophil function. Adipose tissue is metabolically active and inflammatory. Skin folds hold moisture and macerate. And the inflammatory biology of HS overlaps with metabolic disease in a way that is more than coincidence of body habitus.

What has changed recently is that we have a drug class that moves several of those levers at once. Multiple cohorts and case series now report reduced HS disease activity, fewer flares and less pain in patients treated with GLP-1 receptor agonists (4), and a cross-sectional survey found roughly two thirds of respondents reporting improvement in HS-specific measures (5).

I want to be careful here, because the enthusiasm is ahead of the evidence. These are retrospective cohorts and patient-reported surveys, not randomized trials with standardized background therapy. I take the signal seriously in a patient who has both conditions and would be a candidate for the drug anyway. I would not start an incretin in someone whose only indication is their skin.

Smoking is the other lever, and in HS it is a big one. If someone with HS smokes, that is the highest-yield conversation available, and it is not close.

For patients

Notice where they happen. If it is armpits, groin, under the breasts or the buttocks, and it is the same places repeatedly, ask your clinician about hidradenitis suppurativa by name. Naming it is often what gets the diagnosis moving.

If you have a painful lump with a pocket of pus in it, it needs draining. An antibiotic on its own will not finish the job.

If you get recurrent boils and there are other people in your house, ask whether the whole household should be treated rather than just you.

For colleagues

Ask where, not what. Location sorts furuncle from HS from pilonidal faster than any other question, and it is the question that shortens the diagnostic delay.

Household decolonization outperforms individual decolonization, and we mostly still prescribe the individual version.

The GLP-1 and HS literature is worth knowing and worth being careful with. When a patient with both asks whether the drug will help their skin, name the study designs and stop short of promising.

The Bottom Line

Recurrent boils in the armpits, groin, under the breasts or the buttocks are usually hidradenitis suppurativa, and the average person with it waits years for someone to say the word. A true abscess is treated by drainage, with antibiotics as an adjunct rather than a substitute. Recurrent furunculosis is usually a colonization problem, and treating the whole household beats treating the patient. And if the same person has recurrent skin infection, obesity and smoking, the skin is the symptom being presented and the other two are what is driving it.

Related Reading

What is Hidradenitis suppurativa?

Abscesses: What to Do About MRSA

Cellulitis: A Soft Tissue and Skin Infection, Is It MRSA?

Pilonidal Cysts: A Pain in the Rear

What Does Diabetes Do to Your Skin?

How Do You Actually Lose Weight? A Doctor Explains

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Sources

1. Murray N, et al. Equity and Outcome Events in Hidradenitis Suppurativa: Exploring Effect Modifiers Associated with Diagnostic Delay in the Real World. Dermatol Ther (Heidelb). 2024;14(12):3211-3227. PMID 39487935. https://pubmed.ncbi.nlm.nih.gov/39487935/

2. Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America. Clin Infect Dis. 2014;59(2):e10-52. PMID 24973422. https://pubmed.ncbi.nlm.nih.gov/24973422/

3. Fritz SA, Hogan PG, Hayek G, et al. Household versus individual approaches to eradication of community-associated Staphylococcus aureus in children: a randomized trial. Clin Infect Dis. 2012;54(6):743-751. PMID 22198793. https://pubmed.ncbi.nlm.nih.gov/22198793/

4. Rao S, et al. Skin Impacts and Tradeoffs of GLP-1 Therapy: Improved Patient-Reported Outcomes of Inflammatory Skin Disease. Dermatol Ther (Heidelb). 2026. PMID 42579223. https://pubmed.ncbi.nlm.nih.gov/42579223/

5. Javaheri ED, et al. Impact of GLP-1 Receptor Agonists on Hidradenitis Suppurativa: A Cross-Sectional Survey. Int J Dermatol. 2026 Jul 16. PMID 42461155. https://pubmed.ncbi.nlm.nih.gov/42461155/

6. DermNet. Hidradenitis suppurativa. https://dermnetnz.org/topics/hidradenitis-suppurativa