Allergy rast/blood (ige) test reports no milk allergy. is it possible i could still be allergic to dairy? suffering from thick nasal mucus.

Yes: Either RAST (replaced by ImmunoCap IgE) and prick skin testing can miss some food allergies. I often test a patient to the food itself when the history and test findings do not match. Recently I was about to challenge a young boy to walnut (history positive, skin test negative) when the skin test turned out to be highly positive to the actual nut. Mold & mite allergies are more likely in HK.