4 feline house,

I'm sorry I seem to have hit a nerve on the immunology thing. By "black art" I purely meant it takes a very specialised and experienced practitioner to understand the science - I did not mean it as the art of a witch doctor.

I occasionally suffer from serious allergic attacks that I have to go on heavy medication to control. I have had many skin tests, both here and in Germany and the immunologists have failed to identify the allergen I am sensitive to. Stress or viral infections can cause the onset of urticarian reactions (allergy) yet they can not be identified by a simple skin test.