title: [Generalized granuloma annulare or diffuse dermal histiocytosis?].
abstract: Generalized granuloma annulare is a rare variant of granuloma annulare affecting the trunk and extremities with a multitude of lesions. In contrast to localized granuloma annulare, generalized granuloma annulare occurs in older patients, shows a stronger association with diabetes, and is characteristically chronic. Like our 55-year-old patient, most patients present with papules and annular plaques; less often, macular or non-annular lesions may be encountered. Histology often fails to show necrobiotic or necrotic connective tissue changes demarcated by a palisading granuloma. Instead, there are diffuse dermal, band-like or nodular aggregations of histiocytes intermingled with some multinucleated giant cells and a predominantly lymphocytic infiltrate in the periphery. Because of its special characteristics, it has been suggested that generalized granuloma annulare might constitute a separate disease entity and that it should be classed among the primary cutaneous histiocytoses as a diffuse dermal histiocytosis. Using immunohistochemistry to determine the macrophage phenotype of the lesional histiocytes, we have shown that generalized granuloma annulare is not a cutaneous histiocytosis. Neither MS-1 high-molecular-weight protein, a new specific marker for cutaneous non-Langerhans cell histiocytoses, nor CD1a, the well-known marker for Langerhans cells and Langerhans cell histiocytoses, is expressed by the lesional histiocytes of our patient. In contrast, the antigen expression pattern was diagnostic for non-infectious granulomas and was highly similar to that in localized granuloma annulare. In contrast to the successful treatment of localized granuloma annulare reported with intralesional interferon beta-1, systemic treatment with interferon alpha-2b (9 x 10(6) units three times a week) was ineffective.
authors.affiliation: Klinik und Poliklinik für Hautkrankheiten, Westfälischen Wilhelms-Universität, Münster.
authors.forename: L
authors.initials: L
authors.lastname: Kretzschmar
authors.forename: K
authors.initials: K
authors.lastname: Biel
authors.forename: T A
authors.initials: TA
authors.lastname: Luger
authors.forename: S
authors.initials: S
authors.lastname: Goerdt
mesh_terms: D001706:Biopsy; D003937:Diagnosis, Differential; D016460:Granuloma Annulare / Q000175:diagnosis* / Q000473:pathology; D006646:Histiocytosis, Langerhans-Cell / Q000175:diagnosis* / Q000473:pathology; D015616:Histiocytosis, Non-Langerhans-Cell / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000473:pathology