title: Localized papular mucinosis with IgA nephropathy: a case report.
abstract: BACKGROUND
  Papular mucinosis is an idiopathic cutaneous mucinosis. It includes 3 clinicopathologic subsets according to the recent Rongioletti classification: a generalized papular form, a localized form, and atypical forms. The localized form is subdivided into 5 subtypes. The atypical form does not meet the criteria for either the generalized papular form or the localized forms and includes localized forms with monoclonal gammopathy and/or systemic symptoms.
  
  
  METHODS
  We describe a 37-year-old man who had multiple small, waxy papular lesions on the neck for 4 years. One year after the lesions first appeared, he developed IgA nephropathy. No paraproteinemia or thyroid dysfunction was observed. Histologic examination of the skin lesions showed mucin deposits in the upper dermis. Alcian blue-positive mucin was also found in the renal interstitium and around some vessels and capillary loops. A diagnosis of localized papular mucinosis with IgA nephropathy (atypical form) was made after the biopsy.
  
  
  CONCLUSIONS
  The patient showed an unusual manifestation of localized papular mucinosis with the lesions confined to the neck and IgA nephropathy. Alcian blue staining is a useful way to determine kidney involvement of papular mucinosis.
authors.affiliation: Department of Dermatovenereology, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Wang Hou District, Chengdu, People's Republic of China, 610041.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Hanjun
authors.initials: H
authors.lastname: Yang
authors.forename: Yuping
authors.initials: Y
authors.lastname: Ran
mesh_terms: D000328:Adult; D005922:Glomerulonephritis, IGA / Q000150:complications*; D006801:Humans; D008297:Male; D009333:Neck; D053718:Scleromyxedema / Q000150:complications / Q000473:pathology*