What is the updated protocol for diagnosis and management of dissecting cellulitis of the scalp?

Updated Protocol for Diagnosis and Management of Dissecting Cellulitis of the Scalp

Critical Distinction: This is NOT Typical Cellulitis

Dissecting cellulitis of the scalp (perifolliculitis capitis abscedens et suffodiens) is a chronic suppurative scalp disease requiring entirely different management than bacterial cellulitis—antibiotics alone will fail. 1

This condition manifests as follicular and perifollicular inflammatory nodules that suppurate, form intercommunicating sinuses, and lead to permanent scarring alopecia. 1 The disease predominantly affects young African American males aged 22-39 years, typically involving the occiput or vertex. 2

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Diagnostic Approach

Clinical Features to Identify

• Recurrent pustules and nodules on the scalp that suppurate and undermine surrounding tissue 3
• Intercommunicating sinus tracts that form between nodules 1
• Scarring alopecia in affected areas as the disease progresses 1, 3
• Chronic, relapsing course that distinguishes this from acute bacterial infection 1
• Typical locations: occiput or vertex of the scalp 2

Key Diagnostic Pitfall

Do not mistake this for bacterial cellulitis requiring standard antibiotics—the pathophysiology is inflammatory/follicular occlusion, not primarily infectious. 1, 4 Standard cellulitis antibiotics (beta-lactams, vancomycin) are ineffective as primary therapy. 5

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Treatment Algorithm

First-Line Medical Management

Oral isotretinoin at 0.75 mg/kg/day for at least 9 months is the recommended first-line treatment based on the most recent evidence. 2

• This regimen achieved complete healing with good hair regrowth in all seven patients in the most recent case series 2
• Follow-up after recovery ranged from 16-42 months without recurrence 2
• Treatment duration should be at least 9 months to ensure adequate response 2

Alternative First-Line Combination

Oral rifampicin combined with oral isotretinoin represents an effective alternative regimen, particularly for patients requiring additional antimicrobial coverage. 1

• This combination was successfully used in four cases of dissecting cellulitis 1
• Rifampicin addresses any secondary bacterial colonization while isotretinoin targets the underlying follicular pathology 1

When Medical Management Fails

For severe, refractory, intractable disease that fails medical therapy, surgical intervention becomes necessary. 3, 6, 4

Surgical Options (in order of invasiveness):

1. Serial staged excisions with secondary intention healing combined with anti-TNF therapy (adalimumab) 6

   • This conservative approach achieved remission at 20 months follow-up 6
   • Wounds are left to heal by secondary intention between stages 6
   • Anti-TNF therapy is administered concurrently to reduce disease load 6

2. Complete subgaleal excision of affected scalp with split-thickness skin grafting 3, 4

   • Reserved for fulminant presentations or extensive disease 4
   • Vacuum-assisted closure dressing for several days promotes acceptable wound bed before grafting 4
   • Achieves both disease remission and excellent aesthetic outcomes 3

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Specific Treatment Protocols by Severity

Mild to Moderate Disease

• Start with oral isotretinoin 0.75 mg/kg/day for minimum 9 months 2
• Monitor for complete healing of lesions and hair regrowth 2
• Continue treatment until full resolution achieved 2

Moderate Disease with Secondary Infection

• Oral rifampicin PLUS oral isotretinoin 1
• This addresses both inflammatory and infectious components 1

Severe/Refractory Disease

• Initiate anti-TNF therapy (adalimumab) 6
• Consider serial staged excisions if medical management fails after adequate trial 6
• Excisions performed over months to years with secondary intention healing 6

Fulminant Disease

• Radical subgaleal excision of entire affected scalp 4
• Vacuum-assisted closure dressing for several days post-excision 4
• Split-thickness skin grafting at pericranial level once infection cleared 4

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Critical Management Principles

What NOT to Do

• Do not treat with standard cellulitis antibiotics alone (beta-lactams, vancomycin, cephalosporins)—these will fail as monotherapy 5, 1
• Do not use corticosteroids as primary therapy—while mentioned in the literature, they are not first-line 3
• Do not delay surgical consultation in fulminant or medically refractory cases 3, 4

Monitoring and Follow-up

• Assess response at 9 months minimum for isotretinoin therapy 2
• Long-term follow-up required: 16-42 months post-recovery to monitor for recurrence 2
• For surgical patients: Follow for at least 20 months post-final excision 6

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Evidence Quality Note

The evidence base consists entirely of case reports and small case series 1, 3, 6, 4, 2, with the most recent and largest series (7 patients) supporting isotretinoin as first-line therapy. 2 No randomized controlled trials exist for this rare condition. The surgical literature consistently demonstrates that complete excision with reconstruction achieves remission when medical therapy fails. 3, 6, 4