Letter: Subcorneal pustular dermatosis vs pustular psoriasis.

Abstract

To the Editor.— The two cases of subcorneal pustular dermatosis submitted by Johnson and Cripps 1 appear atypical in features other than youthful age alone. The precipitation of eruptions by infection, systemic toxicity with fever, family history of psoriasis (case 2), lesions involving the face and tongue, and lack of response to dapsone but rapid response to systemically administered steroids are atypical for subcorneal pustular dermatosis of Sneddon and Wilkinson 2,3 but characteristic of pustular psoriasis. Additionally, the biopsy features presented by Johnson and Cripps (their Fig 4) reveal a pustule that is distinctly spongiform with pronounced spongiosis and exocytosis of the underlying Malpighian layer. In subcorneal pustular dermatosis, the pustule is superficial, discrete, and nonspongiform with minimal or no spongiosis of the underlying epidermis. 2,3 Johnson and Cripps have considered but rejected the diagnosis of pustular psoriasis in favor of subcorneal pustular dermatosis; I submit that the diagnosis of