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Dissecting Cellulitis — SCE Dermatology MCQ

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HardHair DisordersDissecting CellulitisSCE Dermatology

A 28-year-old man presents with a painful swelling of the scalp. Examination shows a fluctuant, boggy, nodular lesion with multiple sinus tracts discharging seropurulent material on the vertex. Biopsy shows perifollicular neutrophilic infiltrate with follicular occlusion. He also has nodulocystic acne and hidradenitis suppurativa. What is the diagnosis of the scalp lesion?

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Correct answer: A — Dissecting cellulitis of the scalp (perifolliculitis capitis abscedens et suffodiens)

Dissecting cellulitis of the scalp is part of the follicular occlusion tetrad (along with acne conglobata, hidradenitis suppurativa, and pilonidal sinus). It presents with fluctuant, interconnecting abscesses and sinus tracts on the scalp, causing scarring alopecia. The association with nodulocystic acne and HS confirms the follicular occlusion syndrome. Treatment includes oral Isotretinoin (may be effective here, unlike HS), combination Clindamycin/Rifampicin, intralesional corticosteroids, and biologic therapy (Adalimumab). Incision and drainage provides temporary relief. Unlike kerion (fungal), no dermatophyte is found.

Reference: BAD 2012 Cicatricial Alopecia Guidelines; BJD