What is Hidradenitis?

Now for a little biology lesson…

Hidradenitis suppurativa is a disease affecting the apocrine sweat glands that often results in chronically draining sinus tracks and wounds. Over time, the affected areas become scarred and can be afflicted by contracture or tissue immobility. 

The prevalence of hidradenitis suppurativa is approximately 1 in 300 persons, with females affected three times as often as males. The onset of disease is usually during puberty. Hidradenitis suppurativa can significantly impair quality of life because of the pain and discomfort it causes, its limiting effect on daily activities, and the emotional distress suffered by those afflicted.   hidradenitis suppurativa most commonly affects areas that have large numbers of apocrine glands. 

The root cause of hidradenitis suppurativa appears to lie in apocrine gland physiology. Unlike the eccrine glands, the apocrine glands are complicated structures composed of a long secretory coil that originates in the subcutaneous tissue, spans the dermis, and empties into a duct that drains into a hair follicle. The eccrine glands drain directly onto the skin surface. Apocrine glands are found most prominently in hair-bearing areas.

This physiology led researchers to recognize apocrine gland dysfunction as the most likely cause of hidradenitis suppurativa.   The proximal inciting event towards the development of hidradenitis suppurativa is obstruction of the follicular duct or of the apocrine gland itself. This obstruction leads to dilatation of the duct and secretory stasis, which in turn allows bacteria to multiply within the apocrine gland network, causing infection and possible rupture of the glands. Once the gland has ruptured, the infection spreads into surrounding subcutaneous tissue, which can eventually break down to form one large network of chronically draining abscesses and sinuses. At this severe stage, the affected areas can also become fibrous and scarred.