The 2010 guidelines for diagnosis and management food allergy: tests should be based on medical history - do not order large panels of food testing. Sensitization alone is not sufficient for diagnosis of food allergy. Diagnosis is based on the combination of sensitization and clinical symptoms.
Delayed anaphylaxis to meat
Delayed anaphylaxis can occur due to alpha-1, 3 galactose in mammalian meats and milk. This is an example of carbohydrate (not protein) allergy. Alpha-gal sensitization may be triggered by tick or chigger bites. Alpha-gal sensitization may be associated with allergic reactions to cetuximab (food allegy link to drug allergy). Related reading: Delayed mammalian meat–induced anaphylaxis due to galactose-α-1,3-galactose in 5 European patients - JACI, 2011 and Ectoparasite-induced Galactose-α-1,3-Galactose–Specific IgE Is Associated with Anaphylaxis but Not Asthma http://goo.gl/tq86r
Milk protein is found in significant concentrations in products labeled "may contain", "shared equipment", or "shared facility". Recommendation: do not use foods with advisory label. Use caution with unlabeled foods from small companies.
Pregnancy and diet
There is Insufficient evidence to recommend dietary modification during pregnancy. In high risk food allergy families, peanut may be a notable exception.
Soybean oil and soy lecithin are generally well-tolerated in IgE-mediated soy allergy. Soy oil gets a “free pass” for soy allergic patients. Soy lecithin is also not a concern.
There are some patient who can't tolerate the oil and lecithin from soy (if soy-allergic). However, they don't develop anaphylaxis.
Peanut and sesame oils may contain trace amounts of protein (depending on how they are processed), so they should be avoided.
Allergenicity of refined vegetable oils is extremely low http://goo.gl/EzUgp
Food Allergy Cases, Clinical Notes, Mind Maps and Mnemonics at AllergyCases.org
Image source: Roasted peanuts as snack food, Wikipedia, public domain.