DEAR EDITOR, Dissecting cellulitis of the scalp (DCS), also known as perifolliculitis capitis abscedens et suffodiens, is a rare but distinctive, chronic suppurative condition. Fluctuant nodules with interconnecting sinus tracts draining pus and blood can lead to scarring alopecia and keloid formation. DCS can be painful, malodorous and disfiguring. While the exact pathogenesis is unknown, DCS can be associated with acne conglobata, hidradenitis suppurativa (HS) and pilonidal sinus, termed the follicular occlusion tetrad. This relationship suggests a common mechanism, presumed to be follicular hyperkeratosis, poral obstruction, secondary bacterial infection and follicular destruction, with a subsequent neutrophilic and granulomatous inflammatory response. Treatment can be frustrating, and options include isotretinoin, antibiotics, zinc sulfate, local incision and drainage, intralesional triamcinolone injections, laser-assisted epilation and radiation therapy, and radical approaches such as widespread excision with grafting and total scalpectomy. More recently, treatment with tumour necrosis factor (TNF)-a inhibitors has been reported. We report the use of TNF-a antagonists in two patients with DCS. Patient 1, a 48-year-old Afro-Caribbean man, presented with a 20-year history of malodorous and tender scalp lesions. His comorbidities included HS and abnormal liver function tests, with serum gamma-glutamyltransferase levels up to 37 times the upper limit of normal, and serum alanine transaminase (ALT) levels twice the upper limit. He had no history of alcohol abuse, and thorough investigations had not identified structural liver abnormalities. Clinical examination revealed perifollicular scaling, pustule formation and scarring alopecia (Fig. 1). Histopathology demonstrated a heavy mixed dermal infiltrate with predominant neutrophils and numerous plasma cells. Acute inflammatory cells extended into the epidermis and the hair follicle epithelium, with marked folliculitis, focal tufting and deep dermal microabscesses. Periodic acid–Schiff stain, fungal cultures and direct immunofluorescence were negative. A wide range of treatment modalities, including multiple antibiotics, zinc sulfate, dapsone, isotretinoin, systemic corticosteroids, surgical excision and drainage, did not lead to any significant improvement. He was initiated on adalimumab 80 mg on day 0, followed by 40 mg on day 7 and 40 mg every other week thereafter. At the 1-month follow-up, reductions in inflammation and pain were noted. Interestingly, his liver enzymes had improved markedly, with ALT and alkaline phosphatase within the normal range. At 5 months our patient’s Dermatology Life Quality Index (DLQI) had reduced significantly from 21 to 10, with marked reduction in discharge (Fig. 2). Fig 1. Patient 1: close-up view of the occipital scalp with scarring alopecia, pustules and keloid formation.