Hidradenitis suppurativa affects the apocrine-bearing areas of the skin. The onset is variable but usually occurs in the second and third decades of life, coinciding with development of the apocrine glands. The condition is characterised by painful, inflammatory papules and nodules which frequently progress to form abscesses, sinus tracts and hypertrophic scars.The most important non-genetic factors implicated in hidradenitis suppurativa are obesity and smoking.