Sir, Your report on a retailer's decision to withdraw 172 cases of cheese product requires urgent clarification ('FSA in allergy alert over Co-op Cheddars', The Grocer, 5 February).

The product contained high histamine levels, and people eating such product would suffer symptoms similar to an allergic reaction, but this is not an allergy.

The crucial point is that food containing high histamine levels will trigger symptoms in anyone eating it not just those with an allergic tendency. Apart from cheese, fish belonging to the family scombridae, such as mackerel and tuna, can also be susceptible to high histamine levels. Symptoms triggered by histamine poisoning may include a tingling or burning sensation in the mouth, a rash on the upper body and faintness. There may also be vomiting, and diarrhoea.

David Reading, Food Allergy Support