diff --git a/README.md b/README.md
index 3bff53d..e90929c 100644
--- a/README.md
+++ b/README.md
@@ -211,6 +211,16 @@ spec d'origine) précisément pour permettre cet upsert idempotent par nom.
 Liste des 14 allergènes : ceux du règlement UE 1169/2011 (annexe II) — liste
 standard, pas inventée.
 
+**Allergies vs intolérances** (retour fonctionnel, pas dans le doc spec d'origine) :
+`Category.kind` (`AllergenKind` — `ALLERGY` | `INTOLERANCE`) classe chaque allergène.
+Seuls `Gluten` et `Sulfites` sont en `INTOLERANCE` (réaction non-immunitaire
+documentée) ; les 12 autres en `ALLERGY` (réaction immunitaire classique). Classifié
+par substance, pas par utilisateur — un même foyer ne peut pas déclarer "allergie au
+lait" pour un membre et "intolérance au lait" pour un autre ; a suffi pour le besoin
+exprimé, à revoir si ça devient un problème réel. `GET /reference/allergies` renvoie
+`kind` dans chaque `AllergyView` ; `PATCH /profile/allergies` ne change pas (une
+seule liste d'IDs, `kind` ne sert qu'à grouper l'affichage côté client).
+
 ## Foyer & profil — nom, régime, allergènes (apps/api)
 
 Nécessitent tous une session (`requireAuth`) — contrairement aux endpoints de
diff --git a/apps/api/prisma/migrations/20260816235436_add_category_kind/migration.sql b/apps/api/prisma/migrations/20260816235436_add_category_kind/migration.sql
new file mode 100644
index 0000000..f9ed394
--- /dev/null
+++ b/apps/api/prisma/migrations/20260816235436_add_category_kind/migration.sql
@@ -0,0 +1,5 @@
+-- CreateEnum
+CREATE TYPE "AllergenKind" AS ENUM ('ALLERGY', 'INTOLERANCE');
+
+-- AlterTable
+ALTER TABLE "category" ADD COLUMN     "kind" "AllergenKind" NOT NULL DEFAULT 'ALLERGY';
diff --git a/apps/api/prisma/schema.prisma b/apps/api/prisma/schema.prisma
index 2d92313..ebe8716 100644
--- a/apps/api/prisma/schema.prisma
+++ b/apps/api/prisma/schema.prisma
@@ -35,11 +35,22 @@ model Diet {
   @@map("diet")
 }
 
+/// Not in the original spec doc — a category is either a true (IgE-mediated)
+/// allergy or a non-immune intolerance; the UI groups selectable allergens
+/// into two separate lists (`AllergySelect`, apps/web) instead of one flat
+/// "allergies & intolérances" list.
+enum AllergenKind {
+  ALLERGY
+  INTOLERANCE
+}
+
 /// Enumeration-style table, meant to grow over time (e.g. allergy nuances).
-/// `name` is `@unique` for the same reason as `Diet.name` above.
+/// `name` is `@unique` for the same reason as `Diet.name` above. `kind` is
+/// also not in the original spec doc — see {@link AllergenKind}.
 model Category {
-  id   Int    @id @default(autoincrement())
-  name String @unique
+  id   Int          @id @default(autoincrement())
+  name String       @unique
+  kind AllergenKind @default(ALLERGY)
 
   allergies Allergy[]
 
diff --git a/apps/api/src/db/reference-seed-data.ts b/apps/api/src/db/reference-seed-data.ts
index ef0d449..4d4eeaf 100644
--- a/apps/api/src/db/reference-seed-data.ts
+++ b/apps/api/src/db/reference-seed-data.ts
@@ -1,4 +1,4 @@
-import type { PrismaClient } from "@prisma/client";
+import type { AllergenKind, PrismaClient } from "@prisma/client";
 
 // Short, optional-to-pick regime list — `UserProfile.dietId` stays
 // nullable, this is not meant to be exhaustive.
@@ -6,22 +6,26 @@ const DIETS = ["Omnivore", "Végétarien", "Végan", "Pescétarien", "Sans glute
 
 // The 14 allergens EU Regulation 1169/2011 (Annex II) requires food
 // businesses to declare — a standard, defensible reference list rather than
-// an invented one.
-const ALLERGENS = [
-  "Gluten",
-  "Crustacés",
-  "Œufs",
-  "Poissons",
-  "Arachides",
-  "Soja",
-  "Lait",
-  "Fruits à coque",
-  "Céleri",
-  "Moutarde",
-  "Graines de sésame",
-  "Sulfites",
-  "Lupin",
-  "Mollusques",
+// an invented one. Split into ALLERGY (classic IgE-mediated immune
+// reaction) vs INTOLERANCE (non-immune — gluten sensitivity, sulfite
+// sensitivity) per the product decision discussed in chat: only Gluten and
+// Sulfites are commonly-recognized intolerances among the 14; the rest are
+// true allergens.
+const ALLERGENS: Array<{ name: string; kind: AllergenKind }> = [
+  { name: "Gluten", kind: "INTOLERANCE" },
+  { name: "Crustacés", kind: "ALLERGY" },
+  { name: "Œufs", kind: "ALLERGY" },
+  { name: "Poissons", kind: "ALLERGY" },
+  { name: "Arachides", kind: "ALLERGY" },
+  { name: "Soja", kind: "ALLERGY" },
+  { name: "Lait", kind: "ALLERGY" },
+  { name: "Fruits à coque", kind: "ALLERGY" },
+  { name: "Céleri", kind: "ALLERGY" },
+  { name: "Moutarde", kind: "ALLERGY" },
+  { name: "Graines de sésame", kind: "ALLERGY" },
+  { name: "Sulfites", kind: "INTOLERANCE" },
+  { name: "Lupin", kind: "ALLERGY" },
+  { name: "Mollusques", kind: "ALLERGY" },
 ];
 
 /**
@@ -40,12 +44,14 @@ export async function seedReferenceData(prisma: PrismaClient): Promise<void> {
   // `Allergy` itself carries no `name` — it's the selectable instance of a
   // named `Category` (see schema.prisma) — so seeding an allergen means one
   // Category (upserted by name) plus exactly one Allergy row under it,
-  // created only the first time.
-  for (const name of ALLERGENS) {
+  // created only the first time. `update: { kind }` (not `{}`) — a reseed
+  // must correct `kind` on an already-existing category if the
+  // classification above ever changes, not just skip it.
+  for (const { name, kind } of ALLERGENS) {
     const category = await prisma.category.upsert({
       where: { name },
-      update: {},
-      create: { name },
+      update: { kind },
+      create: { name, kind },
     });
     const existing = await prisma.allergy.findFirst({ where: { categoryId: category.id } });
     if (!existing) {
diff --git a/apps/api/src/modules/reference/reference.service.ts b/apps/api/src/modules/reference/reference.service.ts
index 699d304..2c43575 100644
--- a/apps/api/src/modules/reference/reference.service.ts
+++ b/apps/api/src/modules/reference/reference.service.ts
@@ -14,8 +14,12 @@ export async function getDiets(): Promise<DietView[]> {
  */
 export async function getAllergies(): Promise<AllergyView[]> {
   const allergies = await prisma.allergy.findMany({
-    include: { category: { select: { name: true } } },
+    include: { category: { select: { name: true, kind: true } } },
     orderBy: { category: { name: "asc" } },
   });
-  return allergies.map((allergy) => ({ id: allergy.id, name: allergy.category.name }));
+  return allergies.map((allergy) => ({
+    id: allergy.id,
+    name: allergy.category.name,
+    kind: allergy.category.kind,
+  }));
 }
diff --git a/apps/api/test/reference.test.ts b/apps/api/test/reference.test.ts
index d8963a3..85e048b 100644
--- a/apps/api/test/reference.test.ts
+++ b/apps/api/test/reference.test.ts
@@ -33,7 +33,17 @@ describe("Reference data", () => {
       expect(res.status).to.equal(200);
       expect(res.body).to.have.length(14);
       expect(res.body.map((a: { name: string }) => a.name)).to.include("Arachides");
-      expect(res.body[0]).to.have.keys(["id", "name"]);
+      expect(res.body[0]).to.have.keys(["id", "name", "kind"]);
+    });
+
+    it("classifies Gluten and Sulfites as intolerances, the rest as allergies", async () => {
+      const res = await request(app).get("/reference/allergies");
+
+      const byName = (name: string) => res.body.find((a: { name: string }) => a.name === name);
+      expect(byName("Gluten").kind).to.equal("INTOLERANCE");
+      expect(byName("Sulfites").kind).to.equal("INTOLERANCE");
+      expect(byName("Arachides").kind).to.equal("ALLERGY");
+      expect(res.body.filter((a: { kind: string }) => a.kind === "INTOLERANCE")).to.have.length(2);
     });
   });
 });
diff --git a/packages/shared/src/types/reference.ts b/packages/shared/src/types/reference.ts
index f02cfe2..55f0a07 100644
--- a/packages/shared/src/types/reference.ts
+++ b/packages/shared/src/types/reference.ts
@@ -7,15 +7,27 @@ export interface DietView {
   name: string;
 }
 
+/**
+ * Whether an allergen is a true (IgE-mediated) allergy or a non-immune
+ * intolerance — mirrors `AllergenKind` in `schema.prisma`. Declared by hand
+ * here rather than derived from the Prisma enum, same reasoning as
+ * `SafeUserProfile`: `apps/web` must not depend on `@prisma/client`.
+ */
+export type AllergenKind = "ALLERGY" | "INTOLERANCE";
+
 /**
  * A selectable allergen, as returned by `GET /reference/allergies`.
  *
  * `name` is resolved server-side from the parent `Category` — the `Allergy`
  * table itself carries no name of its own (see `schema.prisma`), so this
  * flattens that split away: callers just get `{id, name}` and never need to
- * know a `Category` exists underneath.
+ * know a `Category` exists underneath. `kind` groups allergens into two
+ * separate lists client-side (`AllergySelect`, `apps/web`) rather than one
+ * flat "allergies & intolérances" list — a single `PATCH /profile/allergies`
+ * call still covers both, this is a display grouping only.
  */
 export interface AllergyView {
   id: number;
   name: string;
+  kind: AllergenKind;
 }