Hidradenitis suppurativa (HS) is a chronic inflammatory follicular epithelium disease marked by the presence of painful deep-sitting recurring suppurating lesions in the inverse skin areas of the body.
HS is not a rare condition. The prevalence has been estimated at 1/100 to 1/1,000 individuals in Western populations, with a female: male ratio in the range of 4:1 to 5:1.
HS most commonly begins during the 2nd and 3rd decade of life (mean age = 20-23 years). Onset before puberty or after menopause is rare. Localized itching, burning and redness in characteristic areas (axilla, groin, perianal region, infra mammary region) may be early signs. Lesions rarely develop outside these regions. Subsequently, one or more diagnostic painful deep-sitting nodules and abscesses appear, generally limited to characteristic areas. Lesions are typically recurrent, and evolve to difficult-to-heal, suppurating open lesions and more extensive scarring (”blind boils” in early lesions; abscesses, fistulae, bridged scars and ”tombstone” open comedos in older lesions). Main complications include fistulae, arthropathy, squamous cell carcinoma and amyloidosis (see this term). The degrees in severity, extent and frequency of HS recurrence vary, ranging from extensive constant activity to occasional flares.
HS lesions are due to follicular occlusion which results in the rupture of the dilated follicle and causes a pus-like discharge (containing keratin, corneocytes, hair, sebum products and bacteria) to enter the neighboring tissue, with subsequent bacterial infection. In most cases, HS etiology is unknown, but it is probably multi-factorial. Risk factors include genetic susceptibility, smoking, obesity, shear forces, deregulated immune response, and hormonal anomalies. Equally, a hormonal upheaval (puberty, menstruation, menopause) and/or emotional social stress can trigger a new episode. A familial genetic predisposition has been observed in up to 40% of cases. Rare mutations have been reported in Presenilin-1 (PSEN1), Presenilin Enhancer-2 homolog (PSENEN) and Nicastrin (NCSTN) genes and on 3 loci on chromosome 1, 6 and 19 mostly with autosomal dominant inheritance.
Diagnosis is based on the presence of typical lesions, their specific location, and recurrences. Patients often report a considerable diagnostic delay.
Differential diagnoses include furunculosis, acne conglobate, scrofuloderma, lymphogranuloma venereum, sporotrichosis, Crohn disease, steatocystoma multiplex (see these terms), and other neoplasms.
Genetic counseling should be offered to affected individuals with a strong family history of the disease.
Treatments are developed empirically. Various treatments are available, depending on the stage of HS. Patients are advised to lose weight and stop smoking. Mild cases may benefit from topical clindamycin 1% or oral tetracycline 500 mg b.i.d., and severe cases may benefit from i.v. infliximab (standard schedule using 5 mg/kg) or s.c. adalimumab (40mg every week). Larger case-series strongly suggest the efficacy of oral clindamycin 300 mg b.i.d. combined with oral rifampicine 300 mg b.i.d. Other treatments, reported to be efficient but tested on a smaller scale, include acitretin, dapson, zinc substitution, and topical resorcinol (15%). Physical treatment is often necessary using local excision, Nd:YAG laser or CO2 laser therapy. Radical excision of all fistulas and subcutaneous abscesses is the most definitive treatment in providing long term cure. Secondary healing (leaving surgical wounds open) is argued to sometimes provide better cure rates.
HS has a strong negative impact on the quality of life (physically, mentally, professionally and privately even in a mild form) due to the episodic and often very painful and foul-smelling lesions and the general unsightly symptoms. Life expectancy is normal.
Source: Orphanet: Hidradenitis suppurativa