ArticleParker D, Turk JL.
Int Arch Allergy Appl Immunol. 1978;57(4):289-93.
Intracheal intubation with the soluble metal salts potassium dichromate (K2Cr2O7) and nickel sulphate (NiSO4) causes a delay of up to 8 weeks in the development of delayed hypersensitivity to the specific agent. It is suggested that absorption of sensitizers by the respiratory route may, under certain circumstances, induce a state of specific immunological unresponsiveness, rather than necessarily lead to the development of a state of allergic sensitivity.