D1.32 - The effect of chelation on carmine allergy induced by epicutaneous sensitization to carmine in cosmetics
Background
Carmine is an aluminium and/or calcium-chelated complex form of carminic acid (CA), which is derived from the Dactylopius coccus extract (cochineal), and is globally used as a red-colourant in foods and cosmetics. Although several allergens in carmine allergies, such as CC38K, have been reported, it remains unknown whether chelation affects the allergenicity of carmine. We investigated the effect of chelation on carmine allergies, which induced by epicutaneous sensitisation to carmine contained in cosmetics.
Method
Two female patients diagnosed with carmine allergy based on relevant clinical history and positive skin prick test were enrolled. To identify causative allergens of foods and eyeshadows, we performed IgE-immunoblotting using cochineal or carmine-containing foods, carmine-containing eyeshadows, carmine and CA. In addition, to investigate the influence of chelation on carmine allergy, we performed IgE-immunoblotting using ethylenediaminetetraacetic acid (EDTA) as a chelating agent.
Results
The two patients developed itching, erythema and edema on their eyelids, generalized urticaria, dyspnea and diarrhea immediately after ingesting cochineal-containing foods or carmine-containing drink. IgE-immunoblotting with the carmine using the patients' serum showed a broad band at 86-130 kDa, which were consistent with those using the eyeshadows and causative foods, whereas there is no band using CA. Interestingly, the protein bands using carmine were diminished in a concentration-dependent manner by preincubation in the presence of EDTA. The results indicated that the causative allergens of carmine contained in the eyeshadows could be dechelated by EDTA, reducing its allergenicity.
Conclusion
Carmine contained in cosmetics can cause epicutaneous sensitisation and consequently can induce food anaphylaxis. To prevent sensitisation in carmine allergies, the effect of chelation on allergenicity of carmine should be considered in regards to consumer products.
