Folliculitis and hidradenitis suppurativa (HS) are two skin conditions characterized by red, acne-like rashes. HS is chronic and typically more severe.

Folliculitis is a red or discolored, bumpy, pimple-like rash caused by many different types of infection.

Hidradenitis suppurativa (HS) is a rash that may also resemble acne, but often takes the form of deeper nodules or boils. It’s a chronic condition thought to be tied to genetics and immune system issues, though scientists don’t know for sure.

Here’s what else to know about the difference between these two conditions.

Folliculitis can cause:

  • a red or discolored, itchy, and bumpy rash
  • blisters around the follicles with pus

Hidradenitis suppurativa (HS) may cause:

  • red, purple, or discolored acne-like bumps or deep nodules
  • cysts or boils that contain pus
  • irritation and pain
  • tunnels that form under the skin between lesions

People with darker skin tones may find the redness or discoloration associated with both of these conditions more difficult to see. Learn more about how hidradenitis suppurativa looks on darker skin in this article.

There are many key differences between the conditions, including:

  • Severity: Folliculitis is typically pretty mild and disappears within 1–2 weeks on its own or with topical treatment. HS is a recurring condition that typically requires more extensive medical intervention, including in some cases, surgery.
  • Incidence rate: Folliculitis is more common, and therefore, you’re more likely to get it. HS only affects about 1% of people, while getting folliculitis at some point in life is very common (though exact figures remain unknown).
  • Cause: Folliculitis is typically caused by the Staphylococcus (staph) bacteria or certain types of fungi. The cause of HS is unknown, but it’s thought to be related to your family history and immune system.
  • Contagion: Bacterial folliculitis can be passed through skin-to-skin contact or through items like towels, razors, or clothing. It’s especially passed via wet or moist items since that’s where staph thrives. One type of folliculitis, Pseudomonas folliculitis, also called “hot tub folliculitis,” is caused by a germ commonly found in poorly maintained hot tubs or pools.
  • Rash type: Though both rashes may be characterized by red, pimple-like bumps, outbreaks from HS tend to be deeper and more painful. HS lesions also tend to be larger and may take the form of cysts or boils. Deep, inflamed channels may also form in between HS lesions.
  • Rash location: HS affects the sweat glands and hair follicles and typically occurs on areas where the skin rubs together, like the armpits, groin, anus, inner thighs, under the breasts, or between the buttocks. Folliculitis impacts the hair follicles and is often found on the neck, breasts, buttocks, groin, face, back, arms, or scalp. For example, when folliculitis occurs as the result of being in a pool or hot tub, the rash will typically be more extreme where your swimsuit had contact with your skin.

While folliculitis typically resolves on its own within 1–2 weeks, HS tends to be more challenging to treat.

Applying topical antibiotics or diluted white vinegar can help ease symptoms and side effects associated with folliculitis. If the rash is very severe and doesn’t resolve with topical treatment, other treatments may be recommended, including:

While there’s not yet a cure for HS, there are various methods to help manage it, including:

  • antibiotics
  • biologics
  • steroids
  • pain medication
  • hormone therapy
  • retinoids
  • acne washes
  • topical medication
  • zinc

In some cases, surgery may be necessary to remove painful lesions. Surgeries may include:

  • deroofing
  • electrosurgical peeling
  • total or partial excision

It’s always a good idea to visit a doctor if you have a rash that:

  • is painful or interferes with your daily life
  • doesn’t improve within about 2 weeks
  • disappears then reemerges

A dermatologist can examine the inflamed areas and may be able to diagnose your condition based on its appearance alone. You will also be asked questions about your lifestyle, medical and family history, and other symptoms you may have experienced.

If the lesions are leaking fluid, the doctor may collect a sample and perform lab tests to help identify the cause.

Since HS may become more severe without treatment, it’s a good idea to visit a doctor as soon as possible.

Folliculitis and hidradenitis suppurativa (HS) are two skin conditions characterized by red, acne-like rashes. Folliculitis is caused by a bacterial or fungal infection, while HS is a chronic condition with a hereditary link.

HS outbreaks reemerge over time and tend to be characterized by larger, more severe lesions. Though HS currently has no cure, there are ways to help manage the condition.

Folliculitis is less severe and can resolve on its own within a couple of weeks.

If your rash is painful or persistent, visit a doctor for a diagnosis and treatment as soon as possible.