title: Occupational asthma caused by FD&C blue dye no. 2.
abstract: We report the case of a 55-year-old male who experienced cough, dyspnea, wheezing, and nasal congestion immediately upon exposure to FD&C Blue Dye No. 2 (Indigotine) at work. The patient had worked for 10 years mixing and grinding powdered synthetic red, yellow, and blue dyes for use in foods; symptoms had occurred for 2 years and only with exposure to Indigotine (C16H8N2Na2O8S2), a free flowing blue powder. Prick testing to Indigotine (20 mg/mL) was negative. ELISA failed to detect specific IgE, IgA, IgM, or IgG to Indigotine-HSA conjugates. Bronchial challenge was done according to the method of Pepys et al. beginning with 4 x 10(-4) lactose dilution of Indigotine powder. After 5 minutes of exposure to 4 gm Indigotine/100 gm lactose, the patient developed dyspnea and audible wheezing. At 20 minutes postexposure, there was a 20% decline in FEV1 from prechallenge baseline; no late phase response was observed. A second bronchial challenge with sodium sulfate, the major nondye product additive was negative. To our knowledge, this is the first documented case of occupational asthma due to FD&C Blue Dye No. 2. The pathogenesis is uncertain but does not appear to be IgE mediated.
authors.affiliation: Department of Internal Medicine, University of Cincinnati, OH 45267-0563, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Miller
authors.forename: Z L
authors.initials: ZL
authors.lastname: Lummus
authors.forename: D I
authors.initials: DI
authors.lastname: Bernstein
mesh_terms: D001249:Asthma / Q000139:chemically induced*; D005541:Forced Expiratory Volume; D006801:Humans; D007203:Indigo Carmine / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced*
chemical_list: D007203:Indigo Carmine