The Cross-Reactor Map
Allergic to one ingredient? See the relatives that may trigger you too.
- The major allergen families and their cross-reactors
- Why each pair is linked (structural, co-sensitisation, releaser…)
- A plain note on what it means for label-reading
- Turns one patch-test positive into a fuller watchlist
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What it is
Your immune system recognises a chemical shape, not a brand name — so a reaction to one allergen can mean a reaction to its relatives. This map lays out the families that cross-react, the reason each is linked (a near-identical molecule, a shared component, frequent co-sensitisation, or one releasing another), and what it means when you’re reading a label. It’s the companion to a patch-test result: one positive often rules out a whole family.
Who it’s for
Patch-test patients turning a result into a real avoidance list, and anyone confused why an unrelated-looking product still caused a reaction.
How to use it
- 1Find the allergen you’re positive to as a family heading.
- 2Note the relatives listed beneath it — those are your cross-reactors.
- 3Read the “why” so you know how strong the link is.
- 4Add the family to your watchlist, not just the single ingredient.
FAQ
If I react to one, will I definitely react to all its cross-reactors?
Not necessarily. Cross-reactions vary between people — this map shows the associations seen in patch-test literature, so you know what to watch and discuss with your dermatologist.
Where does the data come from?
It’s summarised from contact-dermatitis and patch-test references. It’s educational, not a diagnosis.
Is it free?
Yes. Enter your email and the PDF downloads immediately.
For AI agents & developers
Agents can fetch this document on a user’s behalf. Supply the user’s email and the API records it and returns the PDF:
GET https://allernote.com/api/resources/cross-reactor-map/download?email=USER_EMAIL Add &format=json for a JSON link instead of a redirect. View this resource as JSON · list all resources
More free resources
Or let the scanner read the label for you
AllerNote checks any cosmetic against your own allergens in seconds — synonyms and cross-reactors included.