Steroid-responsive facial eruption with cornoid lamellae--a possible new entity.

The histopathologic presence of a cornoid lamella is often associated with a diagnosis of porokeratosis. However, this feature is not pathognomonic for porokeratosis and can be found in a number of other dermatologic conditions, which include seborrheic keratosis, verruca vulgaris, actinic keratosis, squamous-cell carcinoma in situ, basal-cell carcinoma, milia, and scar. Notably, the etiology of none of these entities is inflammatory. Wade and Ackerman consider cornoid lamellation to be a distinctive histopathologic reaction pattern that reflects the disordered progression of epidermal cells during cornification. As such, this pattern is not specific for any given disease process. We report a case in which the lesions appeared inflammatory clinically as well as histopathologically, did not resemble porokeratosis despite the presence of cornoid lamellae, and responded to topical glucocorticoids.