I would look into Fed Up with Asthma by Susan Dengate and see what you can do with food but as someone else said you need to take the child to the ER of your local hospital if they are having trouble breathing. When you see your G.P mention these visits and he/she can get confirmation from the hospital that your child was there on which dates and what time for what purpose. This will help the Paed with a diagnosis, and keeping a diary of symptoms,  what time they occur and dates as well as what was eaten, exercise atmosphere etc. will go a long way.

I was told they didnt like to diagnose before 3 but D1 had a night cough two Junes running and so I trotted off to the GP who prescribed ventolin after hearing the symptoms and hearing the family history of asthma etc. She was 2.5 then. The Asthma Clinic Nurse emphasised how important using the medication is as it prevents damage which would happen if left untreated. I imagine you could use that argument (along with family history and symptoms) with your family doctor to get ventolin as a one-off prescription to help until you see the paediatrician. Time to be "one of those nagging mummies" who get what their kids need inspite of the System!

3 of my children are asthmatic since birth they don't like to diagnose until 12 months your child is 21 months so they should be able to diagnose I would seriously go see another GP it is a life threating condition and should not be taken lightly. Who ever said they don't diagnose under 4 or 5  is very misinformed. Your son should be able to have liquid ventolin or even be on a asthma machine by now. My children all started ventolin at 1 years old under this age they don't like to though. I also have written an article on asthma if you would like to read it.

Theres not alot you can do. Try tilting the bed from the bottom, a couple of books or wood blocks at the end of head side of the bed ( I wouldn't recommend putting pillows or cushions under his mattress), keep he's room dry and warm  at nite (do not use a hummidifier as it will make it worse) and try and get into your paed as quickly as possible. If he struggles to breathe, take him to your nearest emergency department for treatment immediately. My daughter (now 6) was diagnosed around about the same age with asthma but keep on them and keep taking him to your nearest ER when he struggles to breathe. It's a real pain having to drag them out all the time but it will make the DRs take notice and he will get treated quicker.

Raven