A range of possibilities!
- Isolated type 1 allergy
- Multiple type 1 fruit allergies – usually to similar fruit but also some common co-sensitivities eg banana/melon/avocado/chestnut/latex group
- Oral allergy syndrome (pollen food syndrome) – esp peach and related stoned fruit, cross reactivity with pollen (so hay fever), sometimes nuts too. Various patterns depending on allergen family.
- Salicylate intolerance (so not allergy) esp cherries, raw tomato, pineapple juice
Some evidence of cross reactivity between raspberry and strawberry but there’s not much evidence to suggest cross reactivity with other berries. There’s a theoretical link with blackberry, and other things in the same family (Rosaceae – massive group of fruit including apples, peach, pear, apricot, cherry).
Only one report of blueberry allergy ever!
Found one paper that said tree nuts, celery and parsley might also be related to berries, but again I think theoretical.