title: Koebner phenomenon in an ANCA-positive patient with pyoderma gangrenosum.
abstract: A male with pyoderma gangrenosum is reported. The clinical and histological features were typical. The initial lesions resolved with characteristic cribriform scars. A few days after the complete recovery, he developed several necrotizing focal lesions localized to the scarred areas. A further histological examination revealed a granulation tissue rich in neutrophils and signs of necrotizing vasculitis. We found a high titer of circulating perinuclear antineutrophil antibodies (p-ANCA), which are a serological marker for various systemic diseases. An immunological circulating factor has been repeatedly suggested to be the "primum movens" of pyoderma gangrenosum. We discuss the unusual clinical presentation interpreted as a Koebner phenomenon and the possible role of immune factors in enhancing circulating-endothelial cell interactions in relation to the pathogenesis of pyoderma gangrenosum.
authors.affiliation: Istituto Dermopatico Immacolata--I.R.C.C.S., Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Papi
authors.forename: B
authors.initials: B
authors.lastname: Didona
authors.forename: L M
authors.initials: LM
authors.lastname: Chinni
authors.forename: T
authors.initials: T
authors.lastname: Gobello
authors.forename: C
authors.initials: C
authors.lastname: Mazzanti
authors.forename: O
authors.initials: O
authors.lastname: De Pità
authors.forename: R
authors.initials: R
authors.lastname: Cavalieri
mesh_terms: D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D017511:Pyoderma Gangrenosum / Q000209:etiology / Q000276:immunology* / Q000473:pathology*; D014657:Vasculitis / Q000209:etiology / Q000276:immunology / Q000473:pathology
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic