A letter came from the consultant at the hospital on Friday - and it makes life complicated.
The blood tests have found nothing. The consultant suggests that the problem may be salicylate hypersensitivity, that is aspirin allergy.
We had excluded that at the beginning because I had taken aspirin without ill-effects. However he has supplied a list drawn up by the British Allergy Foundation of foods that contain high levels of salicylate - and there are an awful lot of them, most of them "healthy" fruits and vegetables.
Much of the list is familiar, some of it is worrying. There is avocado, coconut and almond. There is also yeast, possibly explaining why bread sometimes poses a problem. And there are oranges, peaches and green apples. So wheat and gluten are not problems, almost certainly. I can eat pasta, cake and pastry, but maybe not bread and not fruit cake or macaroons either. Coffee, tea and fruit juice are on the list as are potato skins. It's unmanageable - but I guess small quantities will not kill me and drinks do less harm to the mouth and throat than foods that have to be chewed.
He said to contact him which I tried to do so today but did not get past his secretary. She said they would arrange an appointment with a dietician.
I want to know whether there is any point in taking antihistamines now. She said she would ask him.