Ep 141 – Hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory dermatosis that typically affects areas of pilosebaceous gland-containing skin. In HS, patients often suffer recurrent attacks of discharging and painful lesions that can require multiple courses of antibiotics or surgical drainage. The condition causes significant morbidity, distress and sometimes long-term scarring. In this episode, Dr Roger Henderson looks at the disease process, classification and classical features of HS as well as conservative, medical and surgical treatment options.

Key take-home points

• HS is a chronic persistent or recurrent suppurative disease of unknown aetiology. If left untreated, induration, ulceration and sinus or fistula formation may occur.
• Patients with HS frequently have co-existing conditions such as metabolic syndrome, type 2 diabetes mellitus, inflammatory bowel disease (IBD) and depression.
• The age of diagnosis is usually 18 to 29 but onset may occur soon after puberty in some patients.
• Risk factors include genetics, smoking, obesity, lithium medication, diabetes and IBD.
• The severity of HS can be classified using the Hurley classification, which is based on the configuration of inflammatory lesions and scars.
• Hidradenitis is a clinical diagnosis and there is no specific HS confirmatory test available. The diagnosis requires recurrent painful or suppurating lesions in the characteristic distribution of HS that have flared at least twice in a 6-month period.
• Although the diagnosis is classically made on clinical grounds alone, investigations may include a full blood count to identify any underlying anaemia and blood glucose levels to exclude diabetes.
• Squamous cell cancer may be a consequence of long-standing chronic inflammation in advanced HS.
• Treatment of HS should always be multidisciplinary, including lifestyle advice, medical and sometimes surgical treatment. Early referral to a dermatologist is recommended if the patient does not respond to one to two courses of long-term (3 months) antibiotics in primary care.
• Medical therapy includes use of topical and oral antibiotics, retinoids and – in moderate-to-severe disease – biological agents.
• Anti-TNF therapies have been shown to be effective, and adalimumab and secukinumab are approved by NICE for treating moderate-to-severe HS.
• Simple surgical incision and drainage of painful boils is not effective, as over half recur. Local excision is possible for smaller, quiescent lesions where the clinical margins can be clearly defined.
• The natural course of mild HS can be benign and adequately controlled with relatively simple medical intervention. Limited moderate disease requires more aggressive medical and possible surgical therapy for adequate control, and poorly controlled moderate disease can rapidly progress to more severe disease.

Key references

1. Collier F, et al. BMJ. 2013;346:f2121. doi: 10.1136/bmj.f2121.
2. Zouboulis CC, et al. J Eur Acad Dermatol Venereol. 2015;29(4):619-644. doi: 10.1111/jdv.12966.
3. Ingram JR, et al. Br J Dermatol. 2019;180(5):1009-1017. doi: 10.1111/bjd.17537.
4. Alikhan A, et al. J Am Acad Dermatol. 2009;60(4):539-561. doi: 10.1016/j.jaad.2008.11.911.
5. Gulliver W, et al. Rev Endocr Metab Disord. 2016;17(3):343-351. doi: 10.1007/s11154-016-9328-5.
6. NICE. 2016. https://www.nice.org.uk/guidance/ta392/chapter/1-recommendations.
7. Zouboulis CC, et al. J Eur Acad Dermatol Venereol. 2019;33(1):19-31. doi: 10.1111/jdv.15233.
8. Van der Zee HH, et al. J Am Acad Dermatol. 2010;63(3):475-480. doi: 10.1016/j.jaad.2009.12.018.