Pork triggers eczema through two unusual pathways that both involve cross-reactivity with something else entirely. The first is pork-cat syndrome — living with cats can lead to sensitisation to cat dander proteins, and the immune system may then react to pork because pork contains a protein that is 79% identical to the cat allergen. This causes rapid reactions within 20–60 minutes. The second pathway is alpha-gal syndrome from tick bites, which causes delayed reactions 3–6 hours after eating any mammalian meat including pork.

The timing difference is the key diagnostic clue: fast reaction suggests pork-cat syndrome, slow reaction suggests alpha-gal. For the pork-cat pathway, thorough cooking partially reduces the relevant protein, making well-done pork somewhat safer than undercooked pork.