Stages of HS

Because hidradenitis suppurativa (HS) is often mistaken for an infection, a long delay in diagnosis is not uncommon.1 Dermatologists typically assess the signs and symptoms of HS on a scale - these categories are developed from a clinical measure of severity called the Hurley scale:1,2

Hurley stage I

Single or a few isolated boils without sinus tracts or scarring1,2

  • These tender bumps generally start as firm, pea-sized nodules. Since they typically are red, the nodules are often mistaken for acne, an ingrown hair or sexual disease such as herpes3,4

Hurley stage ll

Recurring boils in multiple areas with scarring and sinus tracts1,2

  • Recurs frequently leaving scars with normal skin in between5,6

Hurley stage lll

Widespread boils with multiple interconnected tracts across the affected area1,2

  • Multiple boils and scars with no normal skin left between them6
  • May be associated with an unpleasant smelling discharge2,7


  1. Jemec GB. Clinical practice. Hidradenitis suppurativa. N Engl J Med 2012;366:158–164.
  2. Revuz J. Hidradenitis suppurativa. J Eur Acad Dermatol Venereol 2009;23:985–998.
  3. NHS Choices. Hidradenitis suppurativa. Available at: Accessed April 2015.
  4. Genetics Home Reference. Hidradenitis suppurativa. U.S. National Library of Medicine. Available at: Accessed April 2015.
  5. Collier F, Smith R, Morton C. Diagnosis and management of hidradenitis suppurativa. BMJ 2013;346:f2121.
  6. Gill L, Williams M, Hamzavi I. Update on hidradenitis suppurativa: connecting the tracts. F1000Prime Rep 2014;6:112.
  7. Dufour ND, Emtestam L, Jemec GB. Hidradenitis suppurativa: a common and burdensome, yet under-recognised, inflammatory skin disease. Postgrad Med J 2014;90:216–221.