I thought i post this to better explain what exactly causes the allergic reaction - its not an additive but a protein:
1. The allergen in the bloodworms is very probably the red hemoglobin-like
protein that gives them their characteristic color. This protein is named
erythrocruorin, and it is also found in many other invertebrate groups,
including annelid worms and molluscs. If I had such an allergy, I'd stay
away from worms too. Quantitavely speaking, a blood worm (i.e., a larval
midge of the genus Chironomus) is little more than a slightly impure
preparation of erythrocruorin---it's there in gigantic amounts. In a way
it's surprising that this protein should be such a strong allergen to some
people, for, immunologically, allergens are usually very potent
antigens---so potent that they can invoke an immune response (an allergy)
upon casual contact. Most of these powerful antigens are proteins that are
bristling with attached carbohydrate molecules that are the targets of the
immune response. These carbohydrate molecules are called haptens. So far
as I can discover, erythrocruarin doesn't have many haptens on its surface,
so why should it provoke such a response---no one seems to know. Perhaps
some of the types of erythrocruorin present in bloodworms (it's there in
multiple molecular forms, much like human hemoglobin) do have attached
haptens, but no one knows this yet..? Other than the one shown below, I
can find no reports in the technical literature on the immunogenicity or
general toxicity of erythorcruorin.
Found
here - but similar information can be found all over the web.