"Feel that I am not being taken seriously"

I feel really angry and feel that I am not being taken seriously.

Last week I was sent to Hillingdon hospital to dermatology and the Dr took my history, then the skin test was performed. The result I received from the doctor is not satisfying, reason is I have really severe allergies to certain foods so that if I eat certain food within seconds I get an anaphylaxis reaction, but the skin prick tests don't show this. It also shows pets test negative; if I live with a pet for 24 hours I will definitely get asthma but the tests show negative. 

I was told different things at hospitals in the past, and given different advice.

So how can we trust these tests.