Five percent 5-aminolevulinic acid photodynamic therapy for the treatment of dissecting cellulitis of the scalp

Dissecting cellulitis of the scalp (DCS) is a rare inflammatory follicular disorder often resistant to conventional treatments. We report three refractory DCS cases that showed inadequate response to >3 months of oral isotretinoin (0.5 mg/kg/day). These patients underwent four sessions of 5% 5-aminolevulinic acid photodynamic therapy (5-ALA-PDT), involving a 3‑hour incubation followed by narrow‐band red light irradiation (633 ± 10 nm, 80 mW/cm², 30 min per session; cumulative dose 500 J/cm²). The treatment led to marked regression of abscesses and inflammation with only mild, manageable burning sensations. These findings suggest that 5-ALA-PDT is a safe and effective alternative for refractory DCS, warranting further studies to optimize treatment protocols.