What Causes Headaches And Rashes On The Face?

i am worried about my daughter in law. she has been sick for basicly 5 yrs! But the last 6 mths have been the worst. She has a constant headache, she has been breaking out in rash s on her face. She s been nausiated most of the time. she s lost allot of weight. and today she woke up with a fever, and has been throwing up! with a wicked headache. She has been going to the dr and all they seem to do is prescribe antibiotics and test for strep. but those tests all come back negative. But things just seem to be getting worse!!