Perifolliculitis Capitis Abscedens et Suffodiens (dissecting cellulitis of the scalp)

Diagnosis: Perifolliculitis Capitis Abscedens et Suffodiens (dissecting cellulitis of the scalp)

Painful cutaneous nodules and patchy alopecia

Clinical Presentation

Painful cutaneous nodules and patchy alopecia

Clinical History

Submitted by Alaa Saad. Originally posted September 11, 2010.

Treatment

See case discussion.

Differential Diagnosis

• Acne vulgaris • Pseudofolliculitis barbae • Hot tub folliculitis (Pseudomonas) • Pityrosporum (Malassezia) folliculitis • Eosinophilic folliculitis (HIV-associated) • Keratosis pilaris • Herpes simplex

Key Learnings

• Most common cause is S. aureus; consider MRSA in recurrent/treatment-resistant cases • Pityrosporum folliculitis: pruritic, monomorphic papules/pustules on trunk — often misdiagnosed as acne • Hot tub folliculitis (Pseudomonas aeruginosa): self-limited, 1-3 days after exposure • Gram-negative folliculitis: consider in acne patients on prolonged antibiotics • Eosinophilic folliculitis: think HIV/immunosuppression (CD4 <300) • Demodex folliculitis: peri-oral/peri-ocular, consider in rosacea-resistant cases

Tags: perifolliculitis, capitis, abscedens, suffodiens, dissecting, cellulitis, the, scalp, alaa saad