Hidradenitis suppurativa (also known as Acne Inversa) is a chronic disorder that affects the skin and occurs at areas where there is skin-to-skin contact and where apocrine sweat glands are present. This disease is characterized by a defect in the follicular epithelium, resulting in the obstruction of the follicular epithelium, which appears as a black-tip mass. Some other characteristics include inflammation, mucus and pus-containing discharge abscess formation, formation of tunnels or sinus tracts connecting abscesses and healing by scarring.
The origin of this disease dates back to 19th century when Velpeau first described this condition in 1839. He encountered it during his clinical experiments on a patient who presented superficial abscesses in the mammary, perianal and axillary regions. He linked this condition to the sweat glands, basing his diagnosis on the clinical presentation of the disease, and he conducted no histopathological studies to confirm it. Before being referred to as hidradenitis suppurativa, this disease was known as Vemeuil’s disease.
Mother physician, Schiefferdecker, also limited this disease to the apocrine glands of the body in 1932. Still another skin specialist Brunsting gave histopathological features of hidradenitis suppurativa in 1939. His histological summary was based on the analysis of specimens taken from the lumen and connective tissues surrounding the apocrine glands. Brunsting described that the main feature of the disease was excessive proliferation of keratin in the follicular epithelium of the gland, with secondary infection, usually bacterial in nature. He too, like his predecessors, associated the disease with acne.
Mother term follicular occlusion triad was introduced by Pillsbury and his colleagues in 1956. It included hidradenitis suppurativa, dissecting cellulitis and acne conglobate as well. Acne tetrad was still another term introduced by Plewig and Kligman in 1975. It included the components of follicular occlusion triad with the addition of pilonidal sinus.
Yet another term introduced by Plewig and Kligman in 1989 was acne inverse. It was quite appropriate title regarding already introduced terms that included follicular occlusion triad or acne tetrad.
As hidradenitis suppurativa is a defect in the follicular epithelium of the gland, it is still commonly referred to as acne inversa, which actually defines the nature of the disease and gives an idea that this disease has localized follicular occlusions.
In United States, the incidence of the disease is one to two percent, while its global level occurrence is estimated to be between one and four percent of the general population.