Ovomucoid

Case notes

Ovomucoid is egg — specifically, it's the dominant allergen in egg white — but the name gives no hint of that. On a label it reads like a technical additive rather than something that came from a shell. It also travels under two other names: Gal d 1, which looks like a lab code, and "egg white protein," which is more transparent but still easy to skim past in a long ingredient list. All three refer to the same thing.

The other reason ovomucoid catches families off guard is that it's heat-stable. Cooking doesn't neutralize it the way it does some other proteins, which is why some egg-allergic children react even to well-baked goods. That matters for label reading because a product being baked, roasted, or otherwise thoroughly cooked doesn't tell you anything useful about whether this particular protein is still present and still recognizable to the immune system. Muffins, crackers, and packaged baked items deserve the same careful read as anything raw.

Ovomucoid also sits alongside other egg-derived names you may run into, including albumin and lysozyme. Knowing that a single allergen can appear under a scientific name, a protein name, and a plain-language name is most of the work of label literacy. If you're keeping notes on reactions, recording the exact wording printed on the package — not just "egg" — makes patterns much easier to spot later and gives you something concrete to bring to your child's clinician.