Why Birch Tree Oral Allergy Syndrome Is Often Misdiagnosed As Flu bejo 6909 Share Why Birch Tree Oral Allergy Syndrome Is Often Misdiagnosed As Flu Oral Allergy Syndrome: diagnosis, symptoms and foods that trigger Oral Allergy Syndrome – ACIR – Allergy, Clinical Immunology & Rheumatology Read also: Future Blood Labs Will Replace Esr Sed Rate Range With Protein Markers