Inflamed, Purulent Axillary Nodules

The disease predominantly affects postpubertal women with an average age of onset between 20 and 30 years.1 It can be debilitating and negatively impact quality of life because the painful lesions involve intimate areas of the body and cause disfigurement.3,4 The pathogenesis of hidradenitis suppurativa involves follicular hyperkeratosis and occlusion, followed by dilation of the follicular unit and subsequent rupture of hair follicles. The release of intraductal follicular contents stimulates inflammation, causing abscess formation, draining tunnels, and residual scarring.3,5 The etiology of hidradenitis suppurativa is not fully understood but is believed to be multifactorial, with genetic, environmental, and hormonal factors.1,3 Many patients (30% to 40%) with hidradenitis suppurativa have a family history of the condition, with an autosomal dominant pattern.1,3,6 Several exogenous factors have also been associated with hidradenitis suppurativa, including obesity, cigarette smoking, and excess androgens.1,4 A carbuncle is a cluster of abscesses under the surface of the skin. Pilonidal cysts are usually solitary, localized, and associated with an abundance of body hair.6 SUMMARY TABLE Condition Characteristics Carbuncle Cluster of abscesses under the surface of the skin; transient with random distribution; usually triggered by an infection Epidermoid cyst Usually asymptomatic; affects the head, neck, back, or genitals Hidradenitis suppurativa Painful nodules with malodorous discharge that progress to abscesses, tunnels (sinus tracts), and scarring; occurs in areas with apocrine glands, such as the axillae, submammary region, and groin Pilonidal disease Solitary cyst localized to the intragluteal region; associated with an abundance of body hairs