In general, allergy skin tests are most reliable for diagnosing allergies to airborne substances, such as pollen, pet dander and dust mites. But because food allergies can be complex, you may need additional tests or procedures. Acetaldehyde dehydrogenase 2 is the enzyme that metabolizes the first metabolic product of alcohol digestion, acetaldehyde. When acetaldehyde accumulates, it produces mast cell...