Hypersensitivity pneumonitis in a technician using Pauli's reagent

A technician working in a medical laboratory used a spray of sodium diazobenzenesulphate (Pauli's reagent) in chromatography. She developed a respiratory illness with both airways obstruction and radiographic and physiological evidence of interstitial pneumonitis. An occupational type of challenge test was followed by both immediate and late bronchial obstructive responses, by a fall in arterial oxygen tension, and by increased radiographic shadowing. Histology of a lung biopsy specimen, a low serum C3, and a postive skin prick test to the reagent suggested that the illness was a hypersensitivity reaction to Pauli's reagent.