title: A case of severe methemoglobinemia caused by hair dye poisoning.
abstract: BACKGROUND
  Hair dyes are widely used and very popular xenobiotics. Most of these products contain paraphenylenediamine (PPD) that can cause methemoglobinemia. We here report a case of severe methemoglobinemia that we treated using large amounts of methylene blue.
  
  
  METHODS
  A 30-year-old man visited a regional hospital with cyanosis. He was congenitally blind and had autism. For several weeks, he had mistaken hair dye for toothpaste. When he arrived at a regional hospital, he was drowsy with cyanosis and his initial serum methemoglobin (MetHb) level was 59.5%. After being treated with 2 mg/kg methylene blue (1 mg/kg × 2 administrations), he was transferred to a tertiary university hospital. Upon presentation at the Emergency Department in the tertiary hospital, his MetHb level was found to be 49.4% and his oxygen saturation was 80%. He was then admitted to the intensive care unit. After treatment with 4 mg/kg methylene blue (1 mg/kg × 4 administrations), he successfully recovered.
  
  
  CONCLUSIONS
  Because PPD can result in serious methemoglobinemia, clinicians should test it in cyanotic patients who have been exposed to hair dye for an extended period.
authors.affiliation: Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: S M
authors.initials: SM
authors.lastname: Ryoo
authors.forename: C H
authors.initials: CH
authors.lastname: Sohn
authors.forename: B J
authors.initials: BJ
authors.lastname: Oh
authors.forename: W Y
authors.initials: WY
authors.lastname: Kim
authors.forename: K S
authors.initials: KS
authors.lastname: Lim
mesh_terms: D000061:Accidents, Home; D000328:Adult; D003490:Cyanosis / Q000209:etiology / Q000517:prevention & control; D004636:Emergency Service, Hospital; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use; D006162:Guanylate Cyclase; D006202:Hair Dyes / Q000633:toxicity*; D006801:Humans; D008297:Male; D008708:Methemoglobinemia / Q000139:chemically induced* / Q000503:physiopathology; D008751:Methylene Blue / Q000008:administration & dosage / Q000627:therapeutic use; D010655:Phenylenediamines / Q000633:toxicity*; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D004791:Enzyme Inhibitors; D006202:Hair Dyes; D010655:Phenylenediamines; D006162:Guanylate Cyclase; D008751:Methylene Blue; C029728:4-phenylenediamine
keywords: Methemoglobinemia; cyanosis; ingestion; methylene blue; paraphenylenediamine