Here's an easy and safe test:
Take a large dose of Vitamin B12 (large dose = anything equal or greater than 1000mcg; I find I need more like 2-4000mcg B12 to counter a sulfite reaction, but it may be different for everyone) when you first feel a headache coming on - preferrably methylcobolamin or hydroxycobolamin, and not the cheaper cyanocobolamin. If your symptoms improve, you likely have a sulfite issue.
Chronic Lyme, Bart., Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut dysmotility & non-specific inflammation, Lupus, Osteoporosis, etc.; G-Tube
Meds: Flagyl, Domperidone, Claritin, Andrographis & other herbs, homeopathy, supplements, etc.