Observational study of chondrodermatitis nodularis helicis treated with methyl aminolevulinate photodynamic therapy

Background Therapies used to treat chondrodermatitis nodularis helicis (CNH), such as surgical excision, pressure relief, or topical steroids report varying degrees of success. Objective We evaluated the response and safety of methyl aminolevulinate (MAL) photodynamic therapy (PDT) in CNH. Methods This retrospective, observational study performed at the University Hospital Ramon y Cajal (Madrid, Spain) and Hospital San Jorge (Huesca, Spain) included all patients diagnosed with CNH and treated with MAL-PDT from 2008 to 2015. Treatment sites were prepared and irradiated as per the conventional MAL-PDT procedure. Results Patients underwent a mean of 2.3 sessions with between-session intervals ranging from 15 days to 1 month. A complete response to PDT was observed in 33 patients (76.7%), who experienced pain relief and resolution of the inflammatory nodule. Lesion recurrence was recorded in 10 patients (23.3%) during the mean follow-up period of 20 months. Receiving ≥2 PDT sessions was significantly associated with a good response (26/28, 93% success rate, P  = .003). Limitations Some limitations of the study are the lack of an established between-session interval, the absence of evaluation of curettage effectiveness and the limited sample size. Discussion The results support the view that PDT is a promising treatment approach for CNH.