Dissecting Cellulitis of the Scalp
Dissecting cellulitis of the scalp (DCS), also called dissecting folliculitis or perifolliculitis capitis abscedens et suffodiens of Hoffmann, is a complex, chronic form of neutrophilic primary cicatricial alopecia. It is marked by deep nodules, soft fluctuant abscesses and interconnecting draining tunnels (sinus tracts) beneath the scalp, and it permanently destroys hair follicles.
DCS belongs to the follicular occlusion tetrad, together with acne conglobata, hidradenitis suppurativa and pilonidal sinus.
DCS develops in four main stages:
- Follicular Hyperkeratosis and Plugging (follicular hyperkeratosis & occlusion): keratin and sebum build up and block the upper part of the follicle (the infundibulum). The blocked follicle widens and fills with trapped secretions.
- Follicle Rupture and Foreign-Body Reaction: the pressure eventually tears the follicle wall. Keratin, sebum and microbes spill into the surrounding dermis, triggering an intense foreign-body granulomatous reaction.
- Abscesses and Interconnecting Tunnels (sinus tracts): neutrophils flood in and release tissue-digesting enzymes (proteases) that destroy the dermis and subcutis, creating deep, fluctuant abscesses. These spread along the subcutaneous plane and join up, forming a complex network of necrotic, pus-draining tunnels under the scalp.
- Secondary Infection and Scarring: although the process starts as sterile inflammation from blockage, tunnels that open onto the skin are easily colonized by Staphylococcus aureus or anaerobic bacteria. This speeds up fibrosis that ultimately destroys the follicular stem cell zone (the bulge region).
At Haute-Derma, we regard dissecting cellulitis as one of the toughest scarring alopecias to manage, because it damages tissue deeply and tends to relapse. By combining detailed trichoscopic assessment with an optimized multi-therapy plan (calming acute inflammation, breaking down fibrotic tunnels and supporting tissue repair), we aim to bring flares under control, save as many recoverable follicles as possible and improve our patients' quality of life.
Clinical Features and Trichoscopy Signs
The condition mainly affects young men (roughly 20–40 years old) and is more common in people with tightly curled, deep-set hair follicles:
- Clinical Signs:
- Fluctuant Nodules: firm red papules or nodules appear first, then quickly fill with pus and feel soft and boggy (fluctuant) when pressed.
- Draining Tunnels (Sinus Tracts): the abscesses connect beneath the scalp. Pressing one nodule can push pus or bloody fluid out of an opening several centimeters away.
- Patchy Scarring Hair Loss: hair over the nodules gradually falls out. As the inflammation settles, it leaves thick or atrophic scars with a smooth, shiny surface and no follicular openings.
- Pain and Odor: patients often live with persistent pain and poor sleep, and feel self-conscious about the characteristic smell of the discharge.
- Trichoscopy Findings:
- 3D Yellow Dots (Soap-Bubble Pattern): the most characteristic trichoscopic sign of DCS, reflecting collections of sebum and pus deep in the subcutis seen through the surface.
- Starburst Vessels (starburst telangiectasia): small dilated vessels radiating around inflamed nodules.
- Target-Like Hairs (targetoid hair) and Hair Casts: hair shafts surrounded by a dark ring of keratin.
- Bridging Scars (bridging scarring): ivory-white fibrous bands linking former follicular openings.
Diagnosis and Specialist Treatment Plan
Because the lesions sit deep in the subcutis and are linked by tunnels, controlling DCS calls for high-dose systemic treatment combined with local procedures.
Diagnostic Workup
- Examination and Trichoscopy: to confirm fluctuant nodules, interconnecting tunnels and 3D yellow dots.
- Microbiology: deep pus samples for Gram stain, culture and antibiotic sensitivity testing, looking especially for drug-resistant S. aureus and anaerobes.
- Imaging (High-Frequency Scalp Ultrasound): shows the depth and size of the tunnels and how much subcutaneous tissue has been destroyed before any surgery.
