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January 1959

Pityriasis Lichenoides et Varioliformis Acuta: Histopathological Evidence That It Is an Entity Distinct from Parapsoriasis

AMA Arch Derm. 1959;79(1):7-16. doi:10.1001/archderm.1959.01560130009002

The belief that pityriasis lichenoides et varioliformis acuta is a variant of parapsoriasis is based mostly on the assumption that there is a histopathological resemblance between the two conditions. Mucha emphasized the microscopic similarities of pityriasis lichenoides et varioliformis acuta and pityriasis lichenoides chronica. Since this original description, many observers, including Habermann, have agreed with Mucha's concept. Recent studies by me have disclosed distinctive microscopic alterations in pityriasis lichenoides et varioliformis acuta. These histopathological changes not only distinguish the two conditions but they indicate a pathogenesis not considered previously. The results of histopathological and histochemical examination in Mucha-Habermann's disease and all forms of parapsoriasis will be discussed. This report will not include a discourse on the morphologic features and clinical behavior of these two diseases.

Materials and Methods

The present investigation was conducted on biopsy tissues obtained from 62 separate patients.