Hidradenitis suppurativa is an inflammatory skin condition that affects hair follicles. It commonly occurs in the underarms because they contain many hair follicles and sweat glands.

Hair follicles get clogged with sweat and keratin, creating painful bumps and sores. The follicles with the infection can expand and create tunnels of infection under the skin.

In addition to their high concentration of sweat glands and follicles, the underarms are particularly prone to hidradenitis suppurativa because they frequently rub against clothes and skin.

Read on to learn about symptoms of hidradenitis suppurativa in the armpits, ways to prevent flare-ups, treatment options, and more.

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Hidradenitis suppurativa is a chronic inflammatory skin condition where the hair follicles get clogged and inflamed, causing painful changes in the skin. The lesions with the infection can look similar to blackheads, cysts, pustules, and lumps. They can also break open and create abscesses.

However, people often mistake hidradenitis suppurativa for other skin conditions, such as acne. According to research, it can take an average of 10 years to get the right diagnosis.

Many people with hidradenitis suppurativa have lesions in their underarms because they are full of hair follicles and sweat glands. The skin friction in this area can cause further irritation.

Hidradenitis suppurativa in the armpits happens when a hair follicle gets blocked with sweat and keratin. It may look similar to a pimple at first. Then, over time, it can enlarge and get more inflamed.

In some cases, it may fill with pus and leak. This can result in the infection spreading to other hair follicles, causing more lesions. If hair follicles expand and spread under the skin, tunnels can form under the skin, spreading the infection further.

Like many chronic conditions, experts do not know what exactly causes hidradenitis suppurativa. However, some factors increase a person’s risk of developing it.

These risk factors include:

  • Family history: Around 30–40% of people with a hidradenitis suppurativa diagnosis have a family member with the same condition.
  • Other inflammatory conditions: Other conditions, particularly inflammatory arthritis, have associations with an increased risk. A 2020 study showed that people with hidradenitis suppurativa had a greater risk of also having ankylosing spondylitis, psoriatic arthritis, and rheumatoid arthritis.
  • Hormonal changes: For many people, the condition starts after puberty. Some people have flare-ups during their menstrual periods and find that the condition subsides after menopause.
  • Metabolic syndrome: An older study from 2013 found that 50.6% of patients with hidradenitis suppurativa also had metabolic syndrome, a group of conditions that increase a person’s risk of diabetes, stroke, coronary heart disease, and more.
  • Body size: People with obesity are more likely to develop hidradenitis suppurativa. However, they should be careful not to try drastic diets or extreme measures. Although dieting may lead to short-term weight loss, long-term dieting may have links to weight gain. Focusing on weight loss also may increase the risk of disordered eating and eating disorders.

It is not always clear what causes flare-ups, so they can be difficult to prevent. However, experts know excessive sweat can increase the risk of clogged hair follicles, so strategies to reduce sweating and keep the skin temperature cooler may help.

Here are some tips that may help prevent hidradenitis suppurativa in the underarm area:

  • Wear loose, breathable clothing to help prevent overheating and excessive sweating.
  • Avoid clothing with rough underarm seams that can cause more irritation.
  • Avoid spending too much time in hot places, which can increase sweating.
  • Use an antimicrobial body wash to gently clean the underarm area.
  • Use caution with shaving, as any cuts may increase the risk of lesions developing.
  • Avoid shaving if there is any sign of a symptom flare in the armpit.
  • Avoid waxing the underarm area, as this can irritate the skin, increasing the risk of a flare.
  • Use unscented, mild antiperspirant to reduce sweating.

It is also important to note that people who smoke are more likely to have more severe hidradenitis suppurativa. Quitting or cutting down, if applicable, may reduce flares and symptom severity for those who smoke.

Learn more about home treatment for hidradenitis suppurativa.

Especially in the early stages, hidradenitis suppurativa can look similar to other skin conditions. A doctor will make a diagnosis according to the appearance and location of lesions and a patient’s symptom history. In some cases, healthcare professionals may collect and analyze a person’s skin or pus samples.

There are several treatment options, including:

  • Steroids: Healthcare professionals may inject steroids into lesions or recommend oral medications. These can help reduce inflammation and pain in severe cases.
  • Antibiotics: Topical antibiotic creams can treat an infection or reduce inflammation. Oral antibiotics may also treat an infection.
  • Hormonal contraceptives: For those who notice more symptoms during their period, these may help prevent flares.
  • Biologic medications: These manage hidradenitis suppurativa by blocking the specific proteins that cause inflammation.
  • Laser hair removal: Although it can be expensive, this may help prevent flares by removing hair follicles and reducing sweating.

Learn more about treatment options.

The underarms are one of the most common areas for hidradenitis suppurativa lesions. This is due to the concentration of sweat glands and hair follicles in this area.

Hidradenitis suppurativa can also develop in the following places:

  • breasts
  • around the anus
  • buttocks
  • groin area
  • inner thighs
  • back
  • scalp
  • behind the ears

Hidradenitis suppurativa is an inflammatory condition of the hair follicles. The armpits are one of the most common sites of hidradenitis suppurativa because the armpits are a concentrated area of sweat glands and hair follicles.

A person may not always be able to avoid a flare, but keeping cool and reducing sweating may help. Several treatment options are available to help people with hidradenitis suppurativa manage the condition.