What Causes Red Rash On Face?

Hi there…
For the last 3 months I have been suffering from some kind of red rash on my face and chest. I'll feel my face and chest area start to get warm and itchy and within seconds my face will be blood-red and very itchy. It usually lasts anywhere from a few minutes to half an hour. It generally happens 3 – 4 times a week and usually in the morning. Along with this 'rash' I have also been waking up with a blocked nose every morning, an occasional runny nose in the day and suffer from constant sneezing throughout the day every day. I visited a homeopath who did a blood allergy test and it came up negative for everything.

Any ideas?