Deeper Seated Than Skin Deep: Report of a Rare Case of Follicular Occlusion Tetrad and a Literature Review.

Follicular occlusion tetrad (FOT) is a clinical syndrome consisting of hidradenitis suppurativa (HS), acne conglobata (AC), dissecting cellulitis of the scalp (DCS), and pilonidal cyst (PC). These entities typically occur independently, but occasionally present simultaneously comprising FOT. The four components share similar pathophysiology affecting the apocrine glands, follicular hyperkeratinization being the hallmark of each entity. Understanding shared similarities of each disease is paramount for the treatment approach as the relapsing and chronic nature of this syndrome can be burdening to patients. We present the case of a 22-year-old obese Hispanic man with a history of tobacco use who presented with worsening skin lesions. The patient developed extensive facial cystic acne 5 years before presentation, followed by left axillary hidradenitis suppurativa lesions two years before the presentation and right axillary involvement one year after. Skin manifestations then expanded to include the lower back, gluteal and perineal areas. The patient was diagnosed with FOT and despite conservative medical management, his lesions failed to improve. He ultimately underwent multiple staged excisional debridement surgeries and skin grafts. Our case underlines the presence of a syndromic association of cutaneous lesions that share a common pathogenesis and emphasizes that this entity requires a multidisciplinary approach. New biologic therapies continue to emerge and may potentially prevent the need for surgical intervention and the burden associated with it.