Fish n milk allergy

Patient: Hello,I get an allergic reaction when i eat fish and dairy products together or separated by less than 2 or 3 hours… i vomit or at least i get stomach ache and nauseamany people here think that you are not supposed to eat them together but i know its a myth … all my family can eat them together except me.there are no information on the internet about that, i just want some information about it like common it is etcthanks a lot.