[Association between UVA1 and PUVA bath therapy and development of malignant melanoma]

After 18 months of intensive UVA1- and bath PUVA therapy for urticaria pigmentosa, a female patient developed a malignant melanoma on the right thigh. This can be taken as further indication that intense UVA1 or PUVA therapy is capable of inducing malignant melanoma, even though this risk has not been completely proven. The total dose of UVA1 was 910 J/cm2, while the total dose of PUVA was 214.4 J/cm2. It is unclear to what extent modified UVA application of long-wave UVA light (UVA1) and modified PUVA therapy (bath PUVA) have a similar risk compared to known data.