Table 1

Hurley severity for hidradenitis suppurativa (HS)

Degree of involvementDefinition27Reported range of patients* affected131625 (%)
Grade IAbscess formation, single or multiple, without sinus tracts and cicatrisation7–68
Grade IIRecurrent abscesses with sinus tracts and cicatrisation; single or multiple widely separated lesions28–83
Grade IIIDiffuse or almost diffuse involvement, or multiple interconnected tracts and abscess across entire area4–22
  • *Populations: Canoui-Poitrine et al13 included 302 consecutive HS referrals in France; Sartorius et al16 included 251 consecutive referrals to a clinic with interest in HS in Sweden (115 with HS); and Matusiak et al25 included 54 Polish patients with HS who qualified for surgical intervention.