title: Leukocytoclastic vasculitis induced by low-dose methotrexate: in vitro evidence for an immunologic mechanism.
abstract: The rare occurrence of methotrexate (MTX)-induced vasculitis has been associated mainly with high or intermediate MTX doses. We report herein a case of cutaneous leukocytoclastic vasculitis (LCV) following treatment with low-dose oral MTX (7.5 mg/week) for rheumatoid arthritis. The histological findings of a cutaneous lesion were consistent with drug-induced vasculitis. The clinical and histological findings, including the temporal relationship between MTX intake and the onset of vasculitis, and the results of withdrawal and rechallenge tests, suggest a causal relationship, and indicate a drug-induced LCV due to MTX. The role of MTX in the induction of the vasculitis was further supported by a positive mast cell degranulation (MCD) test.
authors.affiliation: Department of Dermatology, Soroka, Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. halevy@bgumail.bgu.ac.il
authors.forename: S
authors.initials: S
authors.lastname: Halevy
authors.forename: H
authors.initials: H
authors.lastname: Giryes
authors.forename: I
authors.initials: I
authors.lastname: Avinoach
authors.forename: E
authors.initials: E
authors.lastname: Livni
authors.forename: S
authors.initials: S
authors.lastname: Sukenik
mesh_terms: D000368:Aged; D018501:Antirheumatic Agents / Q000009:adverse effects*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy; D015550:Cell Degranulation / Q000187:drug effects; D004342:Drug Hypersensitivity / Q000209:etiology*; D005260:Female; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D008407:Mast Cells / Q000187:drug effects; D008727:Methotrexate / Q000009:adverse effects*; D017445:Skin Diseases, Vascular / Q000139:chemically induced* / Q000276:immunology / Q000473:pathology; D018366:Vasculitis, Leukocytoclastic, Cutaneous / Q000139:chemically induced* / Q000276:immunology / Q000473:pathology
chemical_list: D018501:Antirheumatic Agents; D008727:Methotrexate