Electron Beam Therapy for Perforating Granuloma Annulare: a case report

Perforating granuloma annulare (PGA) is a rare benign inflammatory dermatosis, representing just 5% of all granuloma annulare (GA) cases. Standardized treatment regimens for refractory PGA remain lacking, and published literature contains scarce reports evaluating electron beam therapy (EBT) for this specific skin disorder. We herein present the case of a 66-year-old Chinese woman with a 5-year history of refractory PGA involving the right forearm, who failed to respond to multiple prior conventional therapies. The patient was initially managed with an EBT-based multimodal regimen, followed by EBT monotherapy for residual lesional changes. Following treatment, the patient achieved marked clinical improvement with near-complete resolution of PGA lesions; no disease recurrence or radiation-associated adverse events were noted throughout the 10-month follow-up period. This case suggests that low-dose superficial EBT may serve as a promising, well-tolerated, individualized therapeutic candidate for refractory PGA. Our findings provide supplementary real-world clinical evidence for research on this rare inflammatory dermatosis, and additional clinical investigations are required to verify the long-term efficacy of EBT and formulate unified treatment regimens for PGA.