A female patient presented with two episodes of apparent dermatitis artefacta. Although it was clear that self-induced lesions were present on both occasions, there was also strong evidence in support of auto-erythrocyte sensitization syndrome on the first occasion and of naproxen-induced pseudoporphyria on the second occasion. The occurrence of two such rare disorders in a single patient is extremely unusual, and we discuss a possible pathogenetic link between them. The case emphasizes that patients with apparent artefactual lesions, or with a previous history of dermatitis artefacta, still require careful evaluation to identify organic disease.