ABSTRACT
Dissecting cellulitis (DC) is a rare chronic disorder of the scalp and, along with hidradenitis suppurativa, acne conglobate, and pilonidal cyst, it forms the follicular occlusion tetrad. The epidemiology of DC is unknown and under diagnosis is possible, especially at the early stage. The disease mainly affects young men of African descent, but according to the recent literature, it is now widespread. The pathogenesis of dissecting cellulitis is presently poorly defined, although it is considered the result of occlusion of the pilosebaceous unit, follicular rupture, and inflammatory cascade. According to some authors, the primary cause can be the obstruction of the follicular ostium or infundibulum. Sinus tracts are typical of DC and they are not present in folliculitis decalvans. Vessel morphology in DC is named “pinpoint-like” because of the presence of a whitish halo. The ultrasound examination of the purulent draining nodules shows dermo-hypodermal fluid collections with multiple fistulous tracts connected to the base of widened follicular units.
