title: Leukocytoclastic Vasculitis Secondary to Pyridostigmine (Mestinon): Report of a Possible First Case.
abstract: Pyridostigmine is an acetylcholinesterase inhibitor commonly used in the treatment of myasthenia gravis. We describe a patient who developed a rash after recently being started on pyridostigmine and give a general review of leukocytoclastic vasculitis.
  
  
  
  A 91-year-old man was diagnosed with ocular myasthenia gravis. He was started on pyridostigmine, and 2 weeks later he developed a rash. The rash was biopsied and found to be secondary to leukocytoclastic vasculitis; the pyridostigmine was stopped, loratadine was started, and the rash resolved.
  
  
  
  Leukocytoclastic vasculitis is commonly caused by a hypersensitivity reaction to medications, or it can be associated with certain medical conditions. We present a brief review of the most common medications and medical conditions known to cause this reaction, but to our knowledge this is the first description of pyridostigmine causing this reaction.
authors.affiliation: Medical Student in Internal Medicine at the University of Otago School of Medicine in Dunedin, New Zealand. singu331@student.otago.ac.nz.
authors.forename: Gunveen
authors.initials: G
authors.lastname: Singh
authors.affiliation: Pathology Registrar at the University of Otago School of Medicine in Dunedin, New Zealand. tim.hodgson@sclabs.co.nz.
authors.forename: Tim
authors.initials: T
authors.lastname: Hodgson
authors.affiliation: Consultant in Medicine at The Dunedin Hospital; an Honorary Clinical Senior Lecturer at the University of Otago School of Medicine in Dunedin, New Zealand; Clinical Assistant Professor of Medicine at Stanford University School of Medicine; and a Hospitalist at the Santa Clara Medical Center in CA. davidclarkemd@mac.com.
authors.forename: David E
authors.initials: DE
authors.lastname: Clarke
mesh_terms: D000369:Aged, 80 and over; D002800:Cholinesterase Inhibitors / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D017336:Loratadine / Q000627:therapeutic use*; D008297:Male; D009157:Myasthenia Gravis / Q000188:drug therapy*; D011729:Pyridostigmine Bromide / Q000009:adverse effects* / Q000627:therapeutic use; D018366:Vasculitis, Leukocytoclastic, Cutaneous / Q000139:chemically induced* / Q000188:drug therapy
chemical_list: D002800:Cholinesterase Inhibitors; D017336:Loratadine; D011729:Pyridostigmine Bromide