With so much conflicting information available on the internet, it can get really difficult to know where to start to help sort through your child symptoms and suspected reactions to food.
If you suspect your child’s symptoms are related to food intolerance, an experienced dietitian is definitely the health professional to see and you don’t need a referral to do this.
If you suspect food allergy, a clinical immunologist should manage the decision making in terms of taking a detailed clinical history and initiating testing (if needed), but most importantly, interpreting all the clinical symptoms and test results appropriately. Thereafter, if there is an allergy, you can see the relevant health professional i.e. an experience dietitian. A dietitian can also help you get started.
To see a specialist, you usually need to see your GP for a referral. They may have someone they work with already or you can search for a specialist in your area here:
Here is some more information on valid allergy testing: https://www.allergy.org.au/health-professionals/papers/unorthodox-techniques-for-diagnosis-and-treatment?highlight=WyJ0ZXN0aW5nIl0=