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Hidradenitis Suppurativa

Key Points

  • Hidradenitis suppurativa (HS) is a chronic inflammatory process affecting skin bearing apocrine glands; the groin, axillae, and inframammary areas are typically involved.
  • The classic lesions of HS include cysts, nodules, sinus tracts, and inflamed abscesses. In rare cases, lesions of pyoderma gangrenosum can occur concurrently within areas of HS or at distant sites.
  • Hidradenitis suppurativa is more prevalent in women. Risk factors for disease include obesity, smoking, and Crohn’s disease. Additional cutaneous associations include acne, pilonidal cyst, acne conglobata, and dissecting cellulitis of the scalp (also known as the follicular occlusion tetrad).
  • Lesions of HS must be monitored for development of squamous cell carcinoma.
  • Progression is often relentless and defies medical management. Early surgery for local and widespread lesions is sometimes the best alternative.

Introduction

Hidradenitis suppurativa (HS) is a chronic inflammatory process that affects skin bearing apocrine glands, typically involving the groin, axillae, and inframammary areas. Areas affected by HS are characteristically marked by heterogeneous skin lesions, ranging from cysts, nodules, sinus tracts, and inflamed abscesses. In rare cases, lesions of pyoderma gangrenosum can occur concurrently within areas of HS or at distant sites.

Women are typically more commonly affected than males and the axilla is the most common site of involvement. A family history of HS is not unusual, and in one small patient cohort, mutations in the gamma secretase complex were identified. Risk factors for disease include obesity, smoking, and Crohn’s disease. Additional cutaneous associations include acne, pilonidal cyst, acne conglobata, and dissecting cellulitis of the scalp (also known as the follicular occlusion tetrad). Lesions of HS must be monitored for development of squamous cell carcinoma, which evolve at sites of chronic inflammation (Marjolin’s ulcer) and in HS, typically occur on the buttocks.

Progression is often relentless and defies medical management. Early surgery for local and widespread lesions is sometimes the best alternative. Hidradenitis suppurativa has a profound impact on patient quality of life. The medical management should be tailored towards the severity and distribution of the disease. Local, mild disease may be managed with topical antibiotics or intralesional corticosteroid injections alone. More severe, extensive disease may require systemic therapy, including short courses of systemic antibiotics and anti-androgen therapy for female patients. Systemic retinoids have not been found to be helpful in this disease. For severe cases of HS, especially with concurrent lesions of pyoderma gangrenosum, systemic immunosuppression with anti-TNF inhibitors may be the best option, though data is limited. To date, the evidence best supports use of antibiotics and TNF-blockade; the use of anti-androgens is only recommended for women with mild to moderate HS who have previously failed antibiotics or have evidence of hyperandrogenism.

Initial Evaluation

Differential diagnosis

Cutaneous Crohn’s disease

Infundibular folliculitis, cysts

Pyoderma gangrenosum

Treatment

First-line therapy: The first-line therapy for mild to moderate hidradenitis suppurativa is topical or systemic antibiotics. For very severe disease, systemic immunosuppression, specifically with anti-TNF-alpha inhibitors, may be first-line.

First steps

Medical

  • Culture draining sinus tracts or abscesses for aerobic and anaerobic bacteria.
  • Give full-dose oral antibiotics effective against the isolated organisms for 1 month. Tetracycline (500 mg t.i.d..), amoxicillin (500 mg b.i.d.), cephalosporins (such as cephalexin 500 mg b.i.d.), and clindamycin (300 mg b.i.d.) have all been used with variable results. The combination of clindamycin with rifampin (both 300 mg b.i.d.) may have slightly increased efficacy over use of a single antimicrobial agent alone.
  • For mild disease, prescribe topical clindamycin solution to be applied to the affected areas twice daily. Combination with a benzoyl peroxide containing gel or wash can help to prevent development of antibiotic-resistant bacterial colonization.
  •  For severe disease, anti-tumor necrosis factor (TNF) alpha inhibitors can be highly effective and is supported by evidence. Of the available modalities, infliximab (5–8 mg/kg given weeks 0, 2, 6, 10, then every 6 to 8 weeks) is superior in its efficacy and should be combined with low-dose methotrexate (5–7.5 mg/ week) in order to avoid the production of infliximab neutralizing antibodies.

Surgical

  • Incise and drain fluctuant abscesses.
  • Inject triamcinolone acetonide 5–10 mg/cc into all non-fluctuant inflammatory areas. This may be repeated at intervals of 2–4 weeks.
  • Local areas may be totally excised, if small, with good results 

Ancillary steps

Encourage obese patients with disease in the intertriginous areas to lose weight.

Subsequent steps

Initial positive response

  • Continue oral antibiotics and taper them slowly over 3-6 months. If the disease recurs, reculture and repeat initial management.
  • Because relapse and persistence is the rule, even patients who have responded well to conservative therapy may be offered more extensive surgical procedures, especially for axillary disease (see below).

Initial treatment failure

Medical treatment

For severe cases only, a limited course of systemic corticosteroids (prednisone 0.5–1 mg/kg/day) for 1–2 weeks will significantly reduce inflammation. When combined with appropriate antibiotics, corticosteroids may also allow the disease to be controlled.

Surgical treatment


  •  Extensive surgical procedures usually offer the only hope for the severely affected.
  • For axillary disease, total excision of the affected axillary areas is of only moderate morbidity and gives excellent results. After their recovery, patients are in general quite satisfied with the long-term, usually permanent remission.
  • Genitocrural hidradenitis can also be totally excised, but often extensive grafting or prolonged healing is required owing to the large areas of involvement. Despite this, after recovery most patients are satisfied.

Pitfalls

  • These disease processes are aggressive, and they require aggressive management to obtain disease control.
  • Tetracycline is contraindicated in pregnancy (after the 14th week of gestation) and in children under the age of 8 due to bone/teeth toxicity.
  • Patients face a twofold risk of carcinoma in these conditions. If the disease is chronic, squamous cell carcinomas, which may be fatal, may occur. In addition, there is an increased risk of cutaneous carcinoma in the areas with chronic wounds or in areas treated with local radiation. Any suspicious non-healing lesion requires biopsy.
  • Inflammatory bowel disease may cause perirectal and/or genital sinus tracts and abscesses. These may be misdiagnosed as hidradenitis.

When to refer to a dermatologist

  • When the diagnosis is not clear.
  • When a biopsy is required to exclude the possibility of cutaneous Crohn’s disease, considered especially in the setting of perianal, buttock, or genitocrural disease.
  • To start systemic immunosuppression with anti-TNF alpha inhibitor medication.

Clinical Cases

Case 1

  • 27-year-old female
  • No significant past medical history and she takes no medications
  • Denies GI symptoms
  • Presents for management of painful cysts on bilateral axilla with purulent drainage

Initial evaluation

  • Obese young female
  • Otherwise healthy
  • Indurated plaques with scattered nodules, cysts, and sinus tracts with moderate erythema in bilateral axillae
  • Diagnosis: hidradenitis suppurativa
  • No skin biopsy is required
  • Treatment options discussed; patient opts for systemic antibiotics. Rifampin 300 mg bid and clindamycin 300 mg b.i.d. is prescribed
  • Intralesional triamcinolone 5 mg/cc injection to active cysts
  • Follow-up in 1 month

Follow-up evaluation

  • The skin lesions are much improved and the patient reports that there is less significant (but still occasional) purulent drainage. Antibiotics are continued for 2 additional weeks
  • Follow-up in 1 month

One-month follow-up evaluation

  • Patient reports significant clinical improvement
  • Systemic antibiotics are discontinued and the patient is switched to topical benzoyl peroxide and clindamycin
  • She continues to return for follow-up every 3-4 months, requiring occasional intralesional triamcinolone 5 mg/cc injection to active cysts and sinus tracts

Case 2

  • 21-year-old male
  • No significant past medical history and she takes no medications
  • Denies GI symptoms
  • Presents for management of painful cysts and plaques with purulent drainage on bilateral axilla, groin, buttocks/perianal area, infra-abdominal pannus

Initial evaluation

  • Obese young male
  • Otherwise healthy
  • Indurated plaques with scattered nodules, cysts, and sinus tracts with moderate erythema in bilateral axillae, inguinal folds, buttocks, perianal area, infra-abdominal pannus
  • Diagnosis: hidradenitis suppurativa
  • No skin biopsy is required
  • Treatment options discussed; patient opts for systemic infliximab. The plan is to start infliximab at 5 mg/kg dose on weeks 0, 2, 6, 10, 16, and every 6 weeks thereafter
  • Pre-treatment labs: complete blood count (CBC) with differential, liver and kidney function tests, hepatitis viral serologies, PPD. A test dose of methotrexate 2.5 mg once a week is given with normal follow-up CBC. The dose is escalated to 5 mg per week
  • Intralesional triamcinolone 5 mg/cc injection to active cysts
  • Referral to dermatologist for ongoing management of infliximab (the patient has complete resolution of symptoms within 3 months).

References

Alhusayen, R., Shear, N.J. (2012) Pharmacologic intervention for hidradenitis suppurativa: what does the evidence say? Amer J Clin Derm, 13: 283-291.

Alikhan, A., Lynch, P.J., Eisen, D.B. (2009) Hidradenitis suppurativa: a comprehensive review (CME), JAAD, 60: 539-561.

Jemec, G. (2012) Clinical practice: Hidradenitis suppurativa, NEJM, 366: 158-164.

Machet, M. et al. (2013) Systemic review of the efficacy and adverse events associated with infliximab treatment of hidradenitis suppurativa in patients with coexistent inflammatory diseases, JAAD, 69(4):649-50.