Hidradenitis suppurativa is a chronic skin condition similar to severe acne. It occurs when sebaceous oil glands or hair follicles become blocked with dead skin cells and fluids from sweat glands. If bacteria enters the blocked areas, blackheads and pus-filled lesions appear. The condition is most likely to affect areas containing apocrine sweat glands, such as the groin or armpit, and can also appear on skin, such as the inner thighs or breasts.
One of the most common symptoms of hidradenitis suppurativa are blackheads or small dark dots on the surface of pores caused by excess oil. Unlike the blackheads associated with mild acne, these often appear in pairs or are pitted into the skin. The skin also typically develops painful red bumps filled with pus or clear liquid known as lesions. They may enlarge before bursting, and often resemble open wounds that are slow to heal.
Other symptoms of the condition occur under the skin. Hard, pea-sized lumps often develop under the skin and may enlarge over time. They can become inflamed and painful, and may remain under the skin for several years. Sinus tracts can form a tunnel network beneath the skin’s surface and prevent any sores from healing.
Hidradenitis suppurativa does not have a proven cause, but hormone levels and genetics are thought to contribute to the condition. Being overweight or smoking cigarettes can also increase an individual’s likelihood of developing the condition. People suffering from Grave’s disease, herpes simplex, or Crohn’s diseases may also be more at risk. Although hidradenitis suppurativa can occur in anyone, it tends to be most common in females between puberty and age 40.
To determine if a patient has the condition, a doctor will examine the skin and take a sample of any fluid or pus from the lesions. The sample is then sent to a laboratory for microscopic examination to determine if the bacteria present is indicative of hidradenitis suppurativa. He or she may also test a blood sample to rule out other skin diseases.
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. Three distinct clinical stages have been defined for the condition.
Stage 1 – solitary or multiple, isolated abscess formation without scarring or sinus tracts
Stage 2 – recurrent abscesses, single or multiple widely separated lesions, with sinus tract formation
Stage 3 – diffuse or broad involvement, with multiple interconnected sinus tracts and abscesses.
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.
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. Weight loss in obese patients and smoking cessation are recommended.
General measures include:
Don't smoke. This is very important. Stopping smoking can lead to improvement within several months.
Follow a low-glycaemic low-dairy diet, and aim for ideal body weight.
Wash with antiseptics or acne preparations to reduce skin carriage of commensal bacteria. Hydrogen peroxide solution and medical grade honey have been found helpful.
Wear loose fitting clothing to avoid friction.
Medical management includes:
Topical anti-acne antibiotics such as clindamycin or erythromycin applied to affected areas in combination with benzoyl peroxide.
Short course of oral antibiotics for acute abscesses (red, hot painful discharging lump) due to staphylococcal infection. Flucloxacillin or dicloxacillin are the most suitable, except in the case of penicillin allergy.
Prolonged courses of tetracycline or metronidazole (minimum 3 months) for their anti-inflammatory action.
Three-month courses of the combination of clindamycin and rifampicin may be the most effective medical treatment in severe cases.
Metformin, usually used in type 2 diabetes, may be beneficial.
Systemic corticosteroids or intralesional corticosteroids (injections directly into the nodules) may reduce severe inflammatory lesions.
In severe cases, the use of biological response mediators such as infliximab, adalimumab, etanercept and other TNFα antagonists, may be worth considering.
Surgical management includes:
Incision and drainage of abscesses – at the very painful pointing stage.
Nodules and abcesses may be de-roofed and scraped out.
Persistent hidradenitis lumps may be excised after several months of conservative treatment (i.e. waiting and/or antibiotics).
Radical excisional surgery is reserved for very severe cases of hidradenitis suppurativa.
Experimentally, laser ablation may be useful in some patients.