Thank you for your inquiry.
The allergens in carmine have been analyzed (1, 2) and more recently cloned (3). However, there have not been extensive studies of crossreactivity. I am not aware of any studies looking at crossreactivity between carmine and shellfish. However, in terms of occupational asthma, carmine does not seem to have crossreactivity with dust mite, and the only known demonstrated crossreactivity of which I am aware is possibly with hornet venom (3).
Thank you again for your inquiry and we hope this response is helpful to you.
1. Chung K, Baker JR Jr, Baldwin JL, Chou A. Identification of carmine allergens among three carmine allergy patients. Allergy. 2001;56(1):73-7.
2. Lizaso MT, Moneo I, Garcia BE, Acero S, Quirce S, Tabar AI. Identification of allergens involved in occupational asthma due to carmine dye. Ann Allergy Asthma Immunol. 2000;84(5):549-52.
3. Ohgiya Y, Arakawa F, Akiyama H, Yoshioka Y, Hayashi Y, Sakai S, Ito S, Yamakawa Y, Ohgiya S, Ikezawa Z, et al. Molecular cloning, expression, and characterization of a major 38-kd cochineal allergen. J Allergy Clin Immunol. 2009 May; 123(5):1157-62, 1162.e1-4. Epub 2009 Feb 26.
Phil Lieberman, M.D.