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Hidradenitis suppurativa: Overview

Also called acne inversa

What is hidradenitis suppurativa?

Hidradenitis suppurativa (HS) is a disease that usually begins as pimple-like bumps on the skin. The pimple-like bumps tend to develop in places that everyday pimples do not appear. HS is most common on the underarms and groin.

Some people say that their HS looks like one of these skin conditions:

  • Pimples

  • Deep-acne like cysts and blackheads

  • Folliculitis (looks like swollen pimple with a hair in the center)

  • Boils

Hidradenitis suppurativa often forms on the underarm.

Hidradenitis suppurativa on the underarm

Getting treatment for HS is important. Early diagnosis and treatment can prevent HS from worsening.

If HS worsens, the pimple-like bumps can grow deep into the skin and become painful. They can rupture, leaking bloodstained pus onto clothing. This fluid often has a foul odor.

As the deep bumps heal, scars can form. Some people develop tunnel-like tracts under their skin. As the skin continues to heal and scar, the scars thicken. When thick scars form in the underarm, moving the arm can be difficult. Thick scars in the groin area can make walking difficult.

Because HS can look a lot like acne, folliculitis, or boils, it is best to see a board-certified dermatologist for a diagnosis. To a dermatologist’s trained eye, the differences between HS and other skin diseases are subtle but obvious. Proper treatment depends on an accurate diagnosis.

Image used with permission of the American Academy of Dermatology National Library of Dermatologic Teaching Slides.

Habif T, Campbell J, Chapman M, et al. In: Dermatology DDxDeck. 2006. Mosby Elsevier. Card #35: Hidradenitis suppurativa.

McMichael A, Sanchez DG, Kelly P. “Hidradenitis Suppurativa.” In: Bolognia JL, Jorizzo JL, Rapini RP, et al. editors. Dermatology 2nd ed. Spain, Mosby Elsevier; 2008. p. 528-9.

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