Carmine (E120), a natural red
dye extracted from the dried females of the insect Dactylopius coccus var. Costa (cochineal), has been reported to cause
hypersensitivity reactions. We report a case of
occupational asthma and
food allergy due to
carmine in a worker not engaged in
dye manufacturing. A 35-year-old nonatopic man, who had worked for 4 years in a spice warehouse, reported
asthma and rhinoconjunctivitis for 5 months, related to
carmine handling in his work. Two weeks before the visit, he reported one similar episode after the ingestion of a red-colored sweet containing
carmine. Peak flow showed drops higher than 25% related to
carmine exposure. Prick tests with the cochineal insect and
carmine were positive, but negative to common aeroallergens, several mites, foods, and spices. The
methacholine test was positive. Specific bronchial challenge test with a cochineal extract was positive with a dual pattern (20% and 24% fall in FEV1). Double-blind oral challenge with E120 was positive. The patient's sera contained specific
IgE for various high-molecular-weight
proteins from the cochineal extract, as shown by immunoblotting.
Carmine proteins can induce
IgE-mediated
food allergy and
occupational asthma in workers using products where its presence could be easily overlooked, as well as in
dye manufacture workers.