To the Editor.—
The mucous membranes are occasionally affected in some cases of psoriasis.1-4 The lips were involved in 2% of 500 patients with psoriasis. Ten patients out of the 500 cases studied had lip psoriasis, while five patients had mucosal psoriasis, ie, 1%, in the form of oral psoriasis and psoriasis linguae (Fig 1).Before discussing the existence of mucosal psoriasis and psoriasis linguae in our patients, which was verified by histologic examination of the materials obtained from skin lesions, mucocutaneous junctions, lips, buccal mucosa, and the tongue itself, we must refer in brief to the salient features of the histopathologic findings in these cases (Fig 2 and 3).
Lip and Mucocutaneous Junction Cases.—
Microscopic examination of the mucosal psoriasis showed a picture more or less similar to psoriasis of the skin. There was hyperkeratosis, parakeratosis, and acanthosis, with elongation of the rete pegs forming test tube-like structures. The