Disseminated superficial actinic porokeratosis with both typical and prurigo nodularis-like lesions

We report a 50-year-old Korean patient who developed a disseminated superficial actinic porokeratosis (DSAP) with two types of lesions. One was a typical DSAP lesion clinically and histopathologically. The other was clinically similar to prurigo nodularis, but histologic examination showed the findings of porokeratosis such as cornoid lamellae and loss of the granular layer in addition to those of chronic lichenified dermatitis, so it could be described as prurigo nodularis-like porokeratosis. The nodular lesions seemed to develop on preexisting typical lesions of DSAP mainly during the summer by the aggravation of pruritic symptoms and scratching associated with sun exposure. Although we could not find any published reports describing lesions like those of our case, we think that such prurigo nodularis-like porokeratosis can develop in patients with DSAP in some situations involving pruritus and scratching.