title: Lupus-like reaction to interferon at the injection site: report of five cases.
abstract: BACKGROUND
  Interferon therapy at the injection sites has been related to different cutaneous lesions including erythema and induration as the most frequent ones. While the glycoprotein induces fatigue, fever and is even believed to precipitate autoimmune disorders such as type I diabetes, thyroid disease and systemic lupus erythematosus, a lupus erythematosus-like histologic reaction at the interferon injection site has never been reported. To our knowledge, a microscopic self-resolving lesion mimicking lupus erythematosus at the injection site of interferon has not been described.
  
  
  RESULTS
  We report five cases of cutaneous lesions at the inoculation site of interferon with a histopathologic lupus erythematosus-like pattern. Three of them were receiving interferon alfa therapy because of a malignant melanoma and the other two patients were receiving interferon beta-1b for multiple sclerosis. Biopsy specimens taken from different lesions showed similar microscopic findings consisting of dermal mucin deposits and dense lymphocytic infiltrates along hair follicles with hydropic degeneration of follicular basal layer.
  
  
  CONCLUSIONS
  Multiple cutaneous lesions related to interferon at the injection site have been reported, but none of them with a histologic lupus-like presentation. In this study we describe five cases in which interferon therapy has induced a resolutive cutaneous lesion mimicking lupus erythematous. This peculiar microscopic pattern has been previously described once before, but interpreted as cutaneous mucinosis.
authors.affiliation: Department of Dermatology, University Hospital, Madrid, Spain.
authors.forename: Itziar
authors.initials: I
authors.lastname: Arrue
authors.forename: Ana
authors.initials: A
authors.lastname: Saiz
authors.forename: Pablo Luis
authors.initials: PL
authors.lastname: Ortiz-Romero
authors.forename: José Luis
authors.initials: JL
authors.lastname: Rodríguez-Peralto
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D003875:Drug Eruptions / Q000209:etiology* / Q000473:pathology; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D000077190:Interferon alpha-2; D000068576:Interferon beta-1b; D016898:Interferon-alpha / Q000009:adverse effects*; D016899:Interferon-beta / Q000009:adverse effects*; D008178:Lupus Erythematosus, Cutaneous / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins; D012867:Skin / Q000187:drug effects* / Q000473:pathology
chemical_list: D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D000068576:Interferon beta-1b; D016899:Interferon-beta