Perifolliculitis capitis abscedens et suffodiens (PCAS) is a chronic skin inflammatory disease characterized by relapsing folliculitis and painful, fluctuant abscesses, sinus tracts, and scars. The treatment of PCAS is challenging and clinical practice varies a lot, and how to choose the best treatment for PCAS is a real problem for clinicians. We reviewed articles providing treatment options for patients with PCAS in different databases. Dermatologists may find this review helpful to meet the challenges of PCAS management, but there is still a lack of authoritative guidelines. In the future, more robust randomized control trials are needed to determine the best treatment for PCAS. K E Y W O R D S biologics, dissecting cellulitis of the scalp (DCS), perifolliculitis capitis abscedens et suffodiens (PCAS), retinoids, treatment option 1 | INTRODUCTION Perifolliculitis capitis abscedens et suffodiens (PCAS), also known as dissecting cellulitis of the scalp (DCS) or Hoffman's disease, is a chronic skin inflammatory disease characterized by relapsing folliculitis and painful, fluctuant abscesses in the scalp that lead to the formation of sinus tracts and scarring. 1 PCAS may occur along with hidradenitis suppurativa (HS), acne conglobate and pilonidal sinus, termed the follicular occlusion tetrad. These four different clinical conditions appear to have common pathogenic events including follicular hyperkeratosis, poral obstruction, dilation and rupture, followed by neutrophilic and granulomatous inflammatory response, bacterial overgrowth, scarring, and sinus tract formations. 2 Treatment of PCAS is challenging and clinical practice varies a lot, while evidence-based treatment guidelines for PCAS are quite rare. Despite a paucity of robust and high-quality data on PCAS, this review focuses on different aspects of PCAS, especially on treatment options for PCAS, providing clinical inspirations for dermatologists.
| CLINICAL MANIFESTATIONS AND HISTOPATHOLOGIC FEATURESLesions of PCAS are folliculitis at an early stage and becoming nodules and abscesses later, primarily on the occipital scalp or vertex, with symptoms of pain, itching or swelling. The nodules and abscesses rapidly develop into interconnecting, fluctuant, boggy sinus tracts, which discharge purulent and bloody secretions with a foul smell. With time, irreversible atrophic or hypertrophic scarring and cicatricial alopecia occur. PCAS presents as a chronic process with frequent episodes. 1,3 The histopathologic characteristics of PCAS usually depend on the clinical manifestation, which can range from early folliculitis, nodules or abscesses to sinus tracts or scars. In the early stage, histopathology findings show an infiltrate of lymphocytes and neutrophils involving the lower half of the dermis and gradually extended downward to subcutaneous fat. The disease progressed with vascular hyperplasia. In the late stage, the deep dermis and subcutaneous fat layer show the histologic characteristics of granuloma and eventually sinus tract and fibrosis develop. 4,5
