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Hidradenitis suppurativa

What is hidradenitis suppurativa?

Hidradenitis suppurativa is an inflammatory skin disease that is characterised by recurrent boil-like lumps (abscesses) that culminate in pus-like discharge, difficult-to-heal open wounds and scarring. It commonly occurs on apocrine sweat gland-bearing skin such as in the groin, the underarms and under the breasts.

It is also known as ‘acne inversa’ (inverse acne). This is probably a better name for the condition, as the term 'hidradenitis' implies it starts as an inflammatory disorder of sweat glands, which is now known to be incorrect.

Hidradenitis suppurativa Hidradenitis suppurativa Hidradenitis suppurativa
Hidradenitis suppurativa Hidradenitis suppurativa Hidradenitis suppurativa
Hidradenitis suppurativa

What causes hidradenitis suppurativa and who gets it?

The exact cause of hidradenitis suppurativa remains unclear. What is understood is that the condition is a disorder of follicular occlusion. This begins with follicular plugging that obstructs the apocrine gland ducts and perifolliculitis around the ducts. This is followed by rupture of the follicular epithelium, bacterial infection and formation of sinus tracts between abscesses under the skin, all which lead to the characteristic symptoms and signs of hidradenitis suppurativa.

The following are thought to play a role in the development of hidradenitis suppurativa.

Women are affected by hidradenitis suppurativa three times as often as men; the reason for this is unknown. The condition most commonly occurs between 20-40 years and coincides with the post-pubertal increase in androgen levels. Disease onset rarely occurs before puberty and after menopause.

In some people, hidradenitis suppurativa makes up one part of follicular occlusion syndrome when it is associated with acne conglobata, dissecting cellulitis and pilonidal sinus.

What are the signs and symptoms of hidradenitis suppurativa?

The extent and severity of the disorder varies widely between individuals. Initially a firm pea-sized nodule (0.5-1.5 cm diameter) resembling acne may appear on one site. These lesions may resolve spontaneously or within hours to days rupture and ooze a pus-like discharge. These may heal without treatment but at a later time new lesions recur in the adjacent area. If uncontrolled, this leads to development of larger lesions (golf ball size), sinus tract formation, and involvement of multiple sites.

Disease may spread to involve less commonly associated sites including the nape of the neck, waistband and inner thighs. Anogenital involvement most commonly affects the groin, mons pubis, vulva, sides of the scrotum, perineum, buttocks and perianal folds. The abscesses and sinus tracts can be painful.

How is severity and extent of hidradenitis assessed?

It is important to use objective measures to describe severity and extent of a disease, particularly when determining the impact of a treatment. Photography of affected areas can also aid follow-up.

Three distinct clinical stages have been defined for hidradenitis (the Hurley stages).

The Sartorius Hidradenitis Suppurativa Score is made by counting involved regions, nodules and sinus tracts.

It is also useful to consider the degree of pain, the number of flares, and the impact on daily life (e.g. using Cardiff Dermatology Life Quality Index questionnaire).

What is the treatment of hidradenitis suppurativa?

Medical management of hidradenitis suppurativa is difficult. The aim is to catch the disease in its early stages and treat and control these milder forms. Antibiotics are usual therapy and long courses may be necessary. Weight loss in obese patients and smoking cessation are recommended.

General measures include:

Medical management includes:

Surgical management includes:

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Author: Vanessa Ngan, staff writer., Dr Amanda Oakley, Dermatologist

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If you have any concerns with your skin or its treatment, see a dermatologist for advice.