Description

• Chronic inflammatory skin disease manifested as recurrent inflammatory nodules, abscesses, sinus tracts, and complex scar formation
• Areas affected are tender, malodorous, often with exudative drainage.
• Has higher risk of concomitant decrease in quality of life secondary to physical, emotional, and psychological stress
• Common in intertriginous skin regions: axillae, groin, perianal, perineal, inframammary skin
• System(s) affected: skin, psychosocial
• Synonym(s): acne inversa; Verneuil disease; apocrinitis; hidradenitis axillaris

Epidemiology

• Predominant sex: female > male (3:1)
• African Americans

Incidence
Peak onset during 2nd and 3rd decades of life but can be found from puberty until age 40 years

Prevalence
1–4% (1)

Etiology and Pathophysiology

• Not fully understood; previously considered a disorder of apocrine glands but more recently thought to be due to a follicular epithelium defect; deregulation of the local immune system may also play a role.
• Hormonally induced ductal keratinocyte proliferation leads to a failure of follicular epithelial shedding, causing follicular occlusion.
• Mechanical stress on skin (intertriginous regions) precipitates follicular rupture and immune response.
• Bacterial involvement is a secondary event.
• Rupture and reepithelialization cause sinus tracts to form.

Genetics

• Familial occurrences suggest single gene transmission (autosomal dominant), but the condition may also be polygenic.
• Estimated 40% of patients have an affected family member.

Risk Factors

• Obesity
• Smoking
• Hyperandrogenism
• Lithium may trigger onset of or exacerbate this condition.

General Prevention

• Lose weight if overweight or obese.
• Smoking cessation
• Avoid constrictive clothing/synthetic fabrics, frictional trauma, heat exposure, excessive sweating, shaving, depilation, and deodorants.
• Use of antiseptic soaps

Commonly Associated Conditions

• Acne vulgaris, acne conglobate
• Perifolliculitis capitis abscedens et suffodiens (dissecting cellulitis of scalp)
• Pilonidal disease
• Metabolic syndrome/obesity
• Polycystic ovary syndrome (PCOS) and androgen dysfunction
• Thyroid disease
• Arthritis and spondyloarthritis (seronegative)
• Inflammatory bowel disease
• Squamous cell carcinoma
• PAPASH syndrome (pyogenic arthritis, pyoderma gangrenosum, acne, and suppurative hydradenitis)
• Type 2 diabetes mellitus