Association of hidradenitis suppurativa and keloid formation: A therapeutic challenge

Abstract

Keloids are a recurrent benign neoplastic condition that result from a traumatic injury to the skin in susceptible individuals. Keloid tissue extends beyond the margins of the injured site; this characteristic distinguishes it from hypertrophic scars. Individuals of African, Hispanic, or Asian descent appear to be at increased risk for keloids.1 Keloids tend to be asymptomatic but may cause pain or itching and have functional, aesthetic, or psychosocial impact on patients.2 The extent of scar formation is influenced by the duration and extent of the inflammatory phase of wound healing, which is longer in patients with hidradenitis suppurativa (HS). The prevalence of keloids among African-American and biracial individuals in the US population is higher than that among white patients.3 Some cutaneous areas are more prone to keloid scar development, likely caused by the vulnerability to trauma such as ear lobes. Other types of direct skin causes include body piercings, burns, lacerations, and surgical wounds. Keloids can also result from inflammatory processes including acne and folliculitis.4 HS is a chronic inflammatory skin disease characterized by persistent or recurrent flares of inflamed painful nodules, sinus tracts, and scars in the intertriginous areas.5 The prevalence of HS is estimated at 1% worldwide with a female/male ratio of 3:1.6 The pathogenesis of HS is not completely understood. Follicular occlusion is believed to initiate the process, trapping commensal bacteria within the follicle. The rupture of the pilosebaceous unit and activation of the innate immune system leads to a chronic tissue inflammation that is difficult to extinguish.7 Characteristic HS lesions commonly heal with different types of scars. Atrophic scars are shallow and, in some cases, cribriform, whereas hypertrophic scars can present as firm plaques or rope-like scars. In individuals prone to keloid, chronic inflammatory HS lesions may lead to keloid formation that may contain both mixed of inflammatory lesions and scars. Two reported cases exist in the literature of keloids in HS and successful treatment with adalimumab.8, 9 We present a case series of 10 more patients with keloid formation in HS wounds and discuss the clinical presentation and therapeutic options.