A practical guide to hidradenitis suppurativa

Hidradenitis suppurativa (HS), also known as acne inversa or Verneuil disease, is a chronic, recurrent, inflammatory occlusive disease affecting the terminal follicular epithelium in apocrine gland–bearing skin areas.¹ HS manifests as painful nodules, abscesses, fistulas, and scarring and often has a severe psychological impact on the affected patient.²

When HS was first identified in the 1800s, it was believed to result from a dysfunction of the sweat glands.³ In 1939, scientists identified the true cause: follicular occlusion.³

Due to its chronic nature, heterogeneity in presentation, and apparent low prevalence,⁴ HS is considered an orphan disease.⁵ Over the past 10 years, there has been a surge in HS research—particularly in medical management—which has provided a better understanding of this condition.^6,7

In this review, we discuss the most updated evidence regarding the diagnosis and treatment of HS to guide the family physician (FP)’s approach to managing this debilitating disease. But first, we offer a word about the etiology and pathophysiology of the condition.

3 events set the stage for hidradenitis suppurativa

Although the exact cause of HS is still unknown, some researchers have hypothesized that HS results from a combination of genetic predisposition and environmental and lifestyle factors.^8-12 The primary mechanism of HS is the obstruction of the terminal follicular epithelium by a keratin plug.^1,13,14 A systematic review of molecular inflammatory pathways involved in HS divides the pathogenesis of HS into 3 events: follicular occlusion followed by dilation, follicular rupture and inflammatory response, and chronic inflammatory state with sinus tracts.⁸

An underreported condition

HS is often underreported and misdiagnosed.^4,15 Globally, the prevalence of HS varies from < 1% to 4%.^15,16 A systematic review with meta-analysis showed a higher prevalence of HS in females compared to males in American and European populations.¹⁷ In the United States, the overall frequency of HS is 0.1%, or 98 per 100,000 persons.¹⁶ The prevalence of HS is highest among patients ages 30 to 39 years; there is decreased prevalence in patients ages 55 years and older.^16,18

Who is at heightened risk?

Recent research has shown a relationship between ethnicity and HS.^16,19,20 African American and biracial groups (defined as African American and White) have a 3-fold and 2-fold greater prevalence of HS, respectively, compared to White patients.¹⁶ However, the prevalence of HS in non-White ethnic groups may be underestimated in clinical trials due to a lack of representation and subgroup analyses based on ethnicity, which may affect generalizability in HS recommendations.²¹

Continue to: Genetic predisposition