title: Psoriasis confined strictly to vitiligo areas--a Koebner-like phenomenon?
abstract: Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.
authors.affiliation: Department of Dermatology, University Hospital of Erlangen, Erlangen, Germany. bergerts@web.de
authors.forename: T G
authors.initials: TG
authors.lastname: Berger
authors.forename: F
authors.initials: F
authors.lastname: Kiesewetter
authors.forename: C
authors.initials: C
authors.lastname: Maczek
authors.forename: N
authors.initials: N
authors.lastname: Bauer
authors.forename: M
authors.initials: M
authors.lastname: Lueftl
authors.forename: G
authors.initials: G
authors.lastname: Schuler
authors.forename: M
authors.initials: M
authors.lastname: Simon
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D005434:Flow Cytometry; D020022:Genetic Predisposition to Disease; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D011565:Psoriasis / Q000150:complications / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism; D014820:Vitiligo / Q000150:complications / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology