Hidradenitis suppurativa is an inflammatory skin disease that affects apocrine gland-bearing skin in the axillae, in the groin, and under the breasts. It is characterized by recurrent boil-like nodules and abscesses that culminate in pus-like discharge, difficult-to-heal open wounds (sinuses) and scarring. Hidradenitis suppurativa also has a significant psychological impact and many patients suffer from impairment of body image, depression and anxiety.
The term hidradenitis implies it starts as an inflammatory disorder of sweat glands, which is now known to be incorrect. Hidradenitis suppurativa is also known as acne inversa.
Who Gets Hidradenitis Suppurativa?
Hidradenitis often starts at puberty and is most active between the ages of 20 and 40 years, and in women, can resolve at menopause. It is three times more common in females than in males. Risk factors include:
Other family members with hidradenitis suppurativa
Obesity and insulin resistance/metabolic syndrome
Inflammatory bowel disease (Crohn disease)
Rare autoinflammatory syndromes associated with abnormalities of PSTPIP1 gene.*
* PAPA syndrome (pyogenic arthritis, pyoderma gangrenosum, and acne), PASH syndrome (pyoderma gangrenosum, acne, suppurative hidradenitis) and PAPASH syndrome (pyogenic arthritis, pyoderma gangrenosum, acne, suppurative hidradenitis).
What Causes Hidradenitis Suppurativa?
Hidradenitis suppurativa is an autoinflammatory disorder. Although the exact cause is not yet understood, contributing factors include:
Friction from clothing and body folds
Aberrant immune response to commensal bacteria
Abnormal cutaneous or follicular microbiome
The release of pro-inflammatory cytokines
Inflammation causing rupture of the follicular wall and destroying apocrine glands and ducts
Secondary bacterial infection
What Are the Signs Hidradenitis Suppurativa?
Hidradenitis can affect single or multiple areas in the armpits, neck, submammary area, and inner thighs. Anogenital involvement most commonly affects the groin, mons pubis, vulva (in females), sides of the scrotum (in males), perineum, buttocks and perianal folds.
Open and closed comedones
Painful firm papules, larger nodules, and pleated ridges
Pustules, fluctuant pseudocysts, and abscesses
Draining sinuses linking inflammatory lesions
Hypertrophic and atrophic scars
Many patients with hidradenitis suppurativa also suffer from other skin disorders, including acne, hirsutism, and psoriasis.
The severity and extent of hidradenitis suppurativa is recorded at assessment and when determining the impact of a treatment. The Hurley system describes three distinct clinical stages:
1. Solitary or multiple, isolated abscess formation without scarring or sinus tracts
2. Recurrent abscesses, single or multiple widely separated lesions, with sinus tract formation
3. Diffuse or broad involvement, with multiple interconnected sinus tracts and abscesses.
Severe Hidradenitis (Hurley Stage 3) Has Been Associated With: