COVID-19 Update. Learn More

Hidradenitis suppurativa

The Toronto Dermatology Centre is one of the best places in Canada to manage the frustrating and often chronic skin condition known as hidradenitis suppurativa. Our staff of Toronto dermatologists offer both a comprehensive assessment and diagnosis of your skin condition, and also discuss all the treatment and preventative options.

Hidradenitis suppurativa (HS), or acne inversa, is a chronic inflammatory follicular-occlusion disorder affecting areas rich in apocrine glands, such as the armpits and anal-genital regions. The disease is characterized by chronic inflammation and soreness, comedones and nodules, mucopurulent odorous discharge, and scarring. Significant psychosocial sequelae can ensue as a result, with depression, shame, and frustration exceedingly common. Approximately 1-2% of the population has the condition, and females appear to be more commonly affected. Young adulthood is the likeliest age of presentation, and it is rarely noted before puberty.

The diagnosis is clinical. The severity of the disease varies significantly from isolated armpit involvement, to involvement including the buttocks, perianal and scrotum or labia. Uncommonly, other areas of the body can be affected. At first, non-inflammatory papules and nodules are present, followed by inflammation and deep tender nodules. Over time, sinus tracts, draining sinuses, and abscesses develop with malodorous discharge. Eventually, fibrosis and hypertrophic or keloid scarring results, as well as contractures. Multiple open comedones (“black heads”) are a hallmark feature.

The cause is based on follicular occlusion affecting apocrine gland-rich areas. At first there is plugging resulting in apocrine gland duct obstruction and perifolliculitis around the ducts. Rupture of follicular epithelium, perhaps aggravated by friction in intertriginous areas, results in spillage of foreign-body material into the dermis which incites an inflammatory response and foreign-body granulomas. Bacterial infection then plays a role in the chronicity, extension and scarring of the condition; the most commonly isolated bacteria are staphylococci. Androgens and genetic factors also appear to play a role. Smoking has been noted to be a major triggering factor and cessation is encouraged. Many patients with HS are overweight and weight loss is also suggested.

Laboratory studies are not usually performed, although an elevated erythrocyte sedimentation rate, white blood cell count, and androgens may be noted, as well as low serum iron. Imaging studies are unnecessary. Bacterial swabs for culture and sensitivity can occasionally be beneficial in selecting antibacterial therapies.

Medical management is recommended in early stages, whereas surgery should be performed as early as possible after the formation of abscesses, fistulas, scars, and sinus tracts. Management of HS consists of general and specific principles. General local hygiene is encouraged with the use of antiseptic soaps and washes (e.g. triclosan), warm compresses, as well as antiperspirant agents that contain aluminum chloride hexahydrate in absolute ethanol (e.g. Drysol®). Loose-fitting clothing is advised, as is weight loss and smoking cessation.

Short-term relief of purulent nodules can be achieved by local incision and drainage. Intralesional triamcinolone acetonide (Kenalog®) is a useful adjunct for painful papulonodules. Topical antibiotics (e.g. clindamycin) and systemic antibiotics (e.g. minocycline, erythromycin, clindamycin) are useful temporizing measures for more widespread involvement. Liquid nitrogen cryotherapy can be tried as an anti-inflammatory adjunct for draining sinuses. Oral retinoids such as isotretinoin 1mg/kg/day, or better yet acitretin 25-50mg/day, can be effective in some patients as maintenance therapy. Some physicians have found success in the use of cyproterone acetate (e.g. Diane-35®) and spironolactone in female patients via their anti-androgen effects. More recently, some biologic medications such as Humira and Remicade have shown benefit for this stubborn condition.

In chronic and recurrent stages of hidradenitis suppurativa (e.g. presence of abscesses, fistulas, sinus tracts, scarring), wide surgical excision and marsupialization is the treatment of choice. Unfortunately, recurrence of disease can occur (up to 25% after wide excision) and new lesions can develop at sites not apparent at the time of surgery. Moreover, scrotal/labial involvement is not as amenable to surgical excision and/or grafting as is the axillae.

Rare, but important sequelae of hidradenitis suppurativa (HS) include: systemic infections, squamous cell carcinoma (if HS > 10yrs), restricted mobility of limbs, anorectal fistulas, and anemia. Unfortunately, hidradenitis suppurativa is a chronic progressive disorder in which spontaneous resolution is rare.