Although there is no cure for this painful condition, pharmacists can play a key role in its management.
Hidradenitis suppurativa (HS), also known as acne inversa or apocrine acne, is a chronic, inflammatory and painful relapsing disease. Although there is no cure, it can be managed to some extent with available treatments.
HS affects the apocrine sweat glands, which are found in the axillae, inguinal and anogenital regions and normally secrete a thick, milky fluid directly into hair follicles. The precise cause of HS is unclear, but it is associated with follicular occlusion of the apocrine duct.
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Typical lesions can initially present as single, painful pea-sized lumps. HS may also present as recurrent papules or nodules situated in the axillae or groin.
HS often first presents between the ages of 20–40 years (as the apocrine glands do not become active until puberty), with mean age of onset of 22 years, and it is believed to affect around 1% of the population. This is probably an under-estimate, because it is often misdiagnosed as boils, abscesses or in-growing hairs.
Risk factors for HS include obesity (the severity increases as weight increases), genetics (roughly a third of patients have a family history of HS), smoking, acne and hirsutism. It is three times more common in women, in whom it typically affects the axillae, groin and sub-mammary regions. In men HS usually occurs in the perineum (between the anus and the scrotum) and perianal region.
There is little evidence to support differences in the prevalence among ethnic groups. However, it has been suggested that the condition is more prevalent in Afro-Caribbean patients, who typically have a higher number of apocrine glands.
Diagnosis is based on three criteria:
- The presence of typical lesions
- Distribution of the lesions
Individual nodules may resolve spontaneously without rupturing or may persist as an inflammatory nodule. Over time, ruptured nodules can fail to heal properly and coalesce to form painful deep dermal abscesses. In more severe cases, larger nodules connect with others through sinus tracts (narrow tunnels under the skin that discharge pus at the skin surface).
The disease is classified by three distinct clinical stages:
- Stage 1 – single or multiple isolated abscesses without scarring or sinus tracts
- Stage 2 – recurrent abscesses with sinus tracts and scarring; single or multiple, widely separated lesions
- Stage 3 – diffuse or almost diffuse involvement; multiple interconnected tracts and abscesses.
The prognosis of HS is variable, although without treatment the condition becomes progressively worse, with scarring and fibrosis limiting mobility, especially in the axillae.
HS is chronic in nature and one study found that the mean duration of symptoms was nearly 19 years. The same study observed that the condition often clears after the menopause in women, and can persist into old age for men.
Around 75% of patients have mild disease (stage 1), which can be managed in primary care.
A wide range of treatment options exists for HS. For patients with stage 1–2 disease, topical and oral antibiotics, such as oral oxytetracycline (500mg twice a day) used intermittently to control flares are appropriate. Antibiotics may also have an anti-inflammatory action and help to reduce secondary infection. For patients not wishing to take oral agents, topical antibiotics represent a viable alternative. In one study of patients with stages 1 and 2 HS, topical clindamycin 1% applied to the lesions twice a day for three months was as effective as oral oxytetracycline (500mg twice daily).
However, a systematic review in 2012 concluded that most treatments were supported by weak or limited clinical evidence. Treatments found to be effective included clindamycin-rifampicin combined therapy, infliximab, monthly Nd:YAG (neodymium-doped yttrium aluminium garnet) laser therapy (for stage 2 and 3); and surgical excision. For patients with mild disease, the review suggested topical clindamycin 1%, in addition to monthly treatment with a carbon dioxide laser on the lesions.
In a recent BMJ article the authors noted that, though trial evidence was lacking, in their own experience, three to six-month courses of lymecycline 408mg daily, erythromycin 500mg twice a day or doxycycline 100mg once a day, had similar effects on abscess and nodule formation as oxytetracycline for patients with stage 1 or 2 HS.
The pharmacist’s role
Patients with suspected HS should be referred to their GP for confirmation of the diagnosis. For patients with mild disease, it is helpful to discuss risk reduction strategies such as smoking cessation, weight loss and wearing loose fitting clothing to help ease irritation8.
The regular use of antiseptic washes (eg, chlorhexidine 4%) applied over the skin and washed off after five minutes can help reduce the risk of bacterial infection. Warm compresses can also be applied to the lesions to encourage the drainage of pus8.
Patients should be advised to avoid shaving in the affected areas, and avoid perfumed deodorants, which can cause irritation8.
Rod Tucker is a commuinty pharmacist in East Yorkshire specialising in skin conditions.
Citation: The Pharmaceutical Journal DOI: 10.1211/PJ.2014.20065556
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