Histopathological patterns in dermatitis artefacta.

Background: Dermatitis artefacta is a relevant and frequently unrecognized clinical condition associated with self-harming behavior, in which unconscious manipulation causes skin lesions. While atypical lesions and an unusual disease course may give rise to clinical suspicion of a self-induced disorder, questioning and examining these patients usually fails to confirm or clarify this suspicion. In this setting, the dermatopathologist may be faced with the question whether there are any histological signs corroborating the diagnosis of dermatitis artefacta.

Methods: We conducted a Pubmed search (without time frame) using the terms "dermatitis artefacta", "factitious/factitial dermatitis", "artefactual skin" in combination with "histology" or "pathology". Given the low number of hits, we extended the search by adding terms related to certain types of injuries (for example, "burn" or "cold") in order to identify specific patterns.

Results: In general, there are only few studies investigating the histological features of factitious skin disorders. Another problem arises from the fact that, even if clinical and histological findings are suggestive of dermatitis artefacta, subsequent confirmation of the exact mechanism of injury is frequently not possible, thus leaving room for speculation. This complicates defining specific histological patterns based on the various types of injuries. Overall, the results of the present study suggest that a factitious disorder should be considered if histological findings include blistering with a mild inflammatory infiltrate, rupture of collagen fibers, multinucleated keratinocytes, or elongated and vertically aligned keratinocytic nuclei.