How is Hidradenitis Suppurativa Diagnosed?

Reviewed by: HU Medical Review Board | Last reviewed: December 2020

You have these strange, itchy, or painful bumps. Their locations in your armpits, groin, inner thighs, buttocks, and sometimes under the breasts are oddly symmetrical. The bumps go away for a while and then recur. Or you develop others like them. You may have hidradenitis suppurativa (HS).

HS is a painful, chronic inflammatory skin disease. The disease begins when clogged hair follicles cause bumps. Over time, the process leads to:1

  • Abscesses
  • Pus
  • Odor
  • Inflammation
  • Tunnels under the skin
  • Scars
  • Impaired mobility

Flares that come and go make the pain and discharge of pus worse.2

HS diagnosis is slow

When you have symptoms of HS, you may first see your primary care physician. Some women talk with a gynecologist first because of the location of lesions (sores) in the groin, the genitals, the area around the anus, and the breasts.3

HS is not very common, and no test identifies the disease. Some doctors may not recognize it. In fact, correct diagnosis takes an average of 7 years. In the meantime, the condition gets worse.4,5

Doctors who are not experienced with HS often confuse it with acne, ingrown hairs, isolated boils, or herpes.2,6

A correct diagnosis at last

Finally getting a diagnosis is a great relief even though you may be confused why the diagnosis took so long and so many visits to different doctors.7

Learning that you have HS does not erase your anxiety and fear of:7,8

  • Random flares
  • Accidentally revealing scars to other people
  • Smelling bad to others
  • Disapproval and social rejection by others
  • Costs of treatment
  • Interference with work

Physical examination

A dermatologist (skin specialist) diagnoses HS by looking for a few key elements in a physical examination.

Lesion types

These types of lesions are common in people with HS:4,9,10

  • Comedones (bumps caused by skin cells, bacteria, and oil blocking hair follicles)
  • Papules (solid bumps)
  • Pustules (bumps with pus)
  • Abscesses (deep, swollen lumps filled with pus)
  • Sinus tracts (narrow tunnels under the skin)


In order from most common to least common location, HS lesions are normally found:4

  • In the armpit
  • On the groin (the folds where the abdomen joins the legs)
  • In area around the anus and between the anus and genitals
  • On the breasts and below the breasts
  • On the buttocks
  • On the pubic area
  • On the chest
  • On the scalp
  • Behind the ears
  • On the eyelids


If an area on one side of the body is affected, the corresponding area on the opposite side is affected too.11


HS lesions recur, or return again and again.12

Severity assessment

Tools have been developed for assessing HS. They include:2,4,13

  • Hurley staging system – the simplest and most widely used by doctors treating patients
  • Modified Sartorius Score (MSS) – based on measuring numbers of lesions and distances between them
  • HS-Physician’s Global Assessment (PGA) – describes 6 stages of disease severity
  • HS Severity Index (HSSI) – scores severity in several categories, such as number of lesions and pain
  • Inflammatory lesion counts – The total number of abscesses and inflammatory bumps are counted and used to calculate response to medical treatment
  • Biopsy or culture – Biopsies and bacterial cultures of pus are used only when a person has atypical HS or a case that does not respond to treatment. Usually cultures of HS do not find bacteria. Sometimes they may help diagnose a secondary infection

Screening for common conditions that occur with HS

Certain conditions and diseases often exist along with HS. Screening for them allows your doctor and care team to provide treatments for your overall health. People with HS should be screened for:4,12,14-19

  • Smoking – increases the risk of HS and worsens HS symptoms
  • Diabetes/metabolic syndrome/obesity – increase risk of cardiovascular-related death. Metabolic syndrome includes large waist size, abnormal triglyceride or cholesterol levels, high blood pressure, and high blood sugar
  • Depression/anxiety – affect quality of life
  • Inflammatory arthritis – higher risk of spondyloarthritis, an inflammatory condition that leads to arthritis in the spine and pelvic joints
  • Inflammatory bowel disease (IBD) – higher risk for Crohn’s disease, a form of IBD
  • Polycystic ovarian syndrome (POCS) – higher risk of POCS, a hormone disorder marked by high levels of androgen (male hormone) in women, irregular menstrual periods, and cysts on the ovaries
  • Follicular occlusion tetrad – 4 inflammatory skin diseases that begin with blocked hair follicles: HS, acne conglobata (severe, scarring acne), pilonidal sinus (a tunnel at the cleft between the buttocks), and scalp cellulitis (infection of skin and underlying tissues)
  • Squamous cell carcinoma (SCC) – higher risk for skin cancer

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