Hi N.,
My Daughter is 16 months and has food sensitivities to cow's milk, sesame seeds, all tree and peanut products, egg white and yolk. We are fortunate enough that she has tolerated soy beans and soy products and wheat.
My first suggestion is to make sure you have seen an expert - an allergist - not just a pediatrician. I love my pediatritian, but allergies are still not dealt with correctly within the traditional medical community. You need an expert and you need a good one.
The most important thing about a child under 3 with bad allergies is to limit exposure to any and all potential allergens. You should also note that a child of 18 months isn't necessary allergic yet, but simply isn't tolerating foods. Your child has an 80% chance of getting rid of all the food allergies by limiting exposure. 18 months is a good time to get tested, if you are not completely positive of the potential allergens.
The classic allergy diet is Lamb, Rice, and Pears. These foods have the least potential for causing allergies. If your child has potential Egg and Milk allergies, you should also avoid beef and chicken. Ham, Turkey and Lamb is your best bet for protein.
IF your child is tolerating wheat - it's a great source of protein and vitamins. We give bagels and whole what bread - but be EXTREMELY CAUTIOUS about where the bread is processed, and ensure they are not made in plants that manufacture nuts or seeds.
TO NOTE about WHOLE FOODS- the majority of their products are made in plants with nuts and other allergens. Be VERY CAREFUL.
One of our issues is getting enough FAT into our daughters diet - you should try to add vegetable oil to her milk substitutes. Rice milk still doesn't have as much protein as soy milk - you might consider going back to an alimentum formula or experimenting with Sheep's or Goat's milk (but I would not do this without consulting an allergist).
Other foods that do well with us: Sweet Potatoes, Plantains, Bananas, Squash, Apples, Pears, Peaches, Brocolli, Cauliflower, my daughter won't eat avacado (hates it) but it's fantastically healthy. For snacks I give her Sweet Potato Chips, Wheat Thins (check for soy on this). AND BELIVE IT OR NOT - FRENCH FRIES (no ketchup)- TONS OF FAT!!!!
You can try potato and Zucchini pancakes - held together with olive or
Pasta has been a big savior for us - try mixing it with some veggies and small pieces of ham to make a rounded meal..
Wholegrain Pancakes made with Banana and Rice Milk - Delicious and healthy (they don't know about syrup).
Don't experiment with Tomatoes, fish, berries, exotic fruits - or anything you're not positive about.
We eat a lot of tofu, beans and rice in our house - but beans are a close relative to peanuts - and tofu of course is SOY, so stay away. I would really try the lamb (my baby doesn't like it though) - My allergist recommended lamb chops - where they could hold it themselves, and have a lot of fun eating it.
Also - RICE, RICE, RICE!!! Brown Rice especially has tons of great stuff in it, and you can mix it with anything. We also eat oatmeal, rice Krispies, Ferina, and Hot rice cereal - add Veggie oil to everything you can!!!!
Good luck - stay calm - Keep Children's benadryl handy (ask doc for the dosage) and GET AN EPIPEN if you don't have one already.
S.
PS - I see a lot of notes on this board to try Vegan cheese (which would have soy, and possibly milk protein believe it or not) and non-dairy creamers (which also can use milk protein). Please remember that any of us writing advice, are not experts and that food allergies can be dangerous. ESPECIALLY - Please don't try nut butters without talking to an allergist - most children who exhibit any sign of peanut allergies are most likely allergic to tree nuts and even if they don't by not exposing them at this age, you can prevent an allergy from beginning. It's very important to talk to real experts about this - don't listen to my advice either without confirming it with a doctor.