Armpit boils can be caused by a condition called ‘hidradenitis suppurativa’, which affects about 1-4% of the population. In fact, if you’ve had boils in your armpit on more than five occasions, it is very likely to be hidradenitis. Typically, if you have hidradenitis you will develop about two painful boils a month, each of which takes about a week to go away, although some people are more badly affected. In really severe cases, boils may be present all the time.
Hidradenitis is not primarily an infection, so you cannot pass it on to anyone else and you will not spread it to other parts of your own body by touch.
What Causes Hidradenitis?
Hidradenitis is caused by blockage of the hair follicles. Once blocked, the hair follicle becomes inflamed and swells up into a nasty, painful, large boil. Bacteria may move in and make the inflammation worse. These are just the common staphylococci bacteria that many healthy people carry on their skin or in their noses.
Hidradenitis happens only in the folds of the body – almost always the armpits or groins, but sometimes the buttock folds and under the breasts. The boils do not always burst; they may just fade away.
You should not worry that it is caused by lack of hygiene – this is not the case. No one knows what the cause is. It runs in some families, so it may be partly genetic in some people. Hormones may be involved, because it is more common in women, is often worse before a woman’s period and improves after the menopause.
What to Do
Try to avoid too much stress, although of course this is easier said than done. You may have already noticed that the boils tend to be worse if you are stressed, so it makes sense to be as ‘laid back’ as you can.
Stop smoking. Hidradenitis is more common in smokers, so most experts recommend that you should give up smoking.
What about deodorants? I didn’t know whether deodorants can worsen hidradenitis, so I asked Dr Jan von der Werth, Consultant Dermatologist at Lincoln County Hospital, UK, who is an expert on hidradenitis. “A few of my patients report that deodorants make it worse, but for most people they don’t cause any problem,” he said. Deodorants are likely to sting the area if it is an aerosol, so best a non-fragranced, non-perfumed roll-on variety.
If you have a flare-up you may find that a hot bath or applying a hot flannel is helpful.
See your doctor. Next time you have a flare-up you should see your doctor, to check you really have hidradenitis. If it is very painful, your doctor might give you corticosteroid tablets for 3 or 4 days. In the UK, consider use of an antibiotic solution twice daily, and/or an oral antibiotic for 12 weeks once or twice daily and assess the response (BAD guidelines on HS 2019).
Your doctor can refer you to a dermatologist (skin specialist) for advice about long-term treatment. Ideally, your doctor should try to find a dermatologist who is particularly interested in the condition and knows all the treatment options.
Some treatment options. There are several possibilities, and what works for one person may be useless for someone else.
- A hormone pill is sometimes used.
- For some people, a long-term tetracycline-type or erythromycin-type antibiotic is beneficial, or a clindamycin cream, even though the basic cause of the condition is not an infection. “We don’t really know why these long-term antibiotics are so helpful in some cases,” says Dr von der Werth. “It is probably not simply their antibacterial action. They probably have a separate anti-inflammatory action.” After stopping an antibiotic, the problem may return so it is not an absolute cure – it just holds it at bay.
- The next stage would be a combination of two strong antibiotics for 12 weeks.
- Retinoid drugs (as used in acne) can have an excellent result but need very careful thought. The dermatologist would not prescribe it for a woman if there was any possibility that she could become pregnant because it damages the developing foetus.
- ‘Anti-TNF drugs’, such as infliximab, can help some people. These are a newish type of drug, sometimes used in severe skin conditions where there is inflammation. The treatment is complicated, because the drug has to be infused into a vein and repeated every month or two (MIMS Dermatology 2010;6:46–48). Therefore it would be tried only in severe cases, and more research is needed to see how effective it really is. These anti-TNF drugs have been around now for a long time and the safety data is good, but to qualify for them you need to have failed the standard treatments mentioned above, and it needs to be prescribed by a specialist.
- Surgery is an option if your condition is really severe. The surgeon would aim to get rid of the hair follicles in the area by taking away a large piece of skin and letting it scar as it heals. Unfortunately, after surgery the boils reappear at a new site in about a quarter of people (MIMS Dermatology 2010;6:46–48).
- Laser surgery or freezing (cryotherapy) therapy is another method of destroying the follicles.
First published on: embarrassingproblems.com
Reviewed and edited by: Fiona Elliott
Last updated: December 2020