[jacinda]

To be on the safe side, I'd avoid giving him any more berries while the paediatrician is away. No one is allergic to something they've never tasted. The body has to have been exposed to it before. For some reason the immune system reclassifies a particular food/allergen as being dangerous to the body, even though that person has eaten it before with no problems. The next time it enters the body, it triggers the red flag for danger, and the allergic response starts. Allergic reactions can get worse each time, especially when it's a new allergy starting. Now that the body has decided to treat the food/pesticide as an allergen, it will recognise it straight away, and the attacks might get really serious a lot quicker than you think. It's a worse case scenario, but you want to be careful and only expose him to the allergen under controlled conditions from here on in just to be safe.