*3.1. Introducing New Foods into Infants' Diet*

According to existing recommendations, parents were suggested to expand the infants' diet after 4 months (2008: EAACI, AAP, 2009—ESPGHAN, 2010—NIAID). Most parents did so (89%), while others began introducing new foods after their babies were 5 months old (Table 4).

All new foods were given at home by parents for 4 days, at a dose consistent with typical intake. The absence of an adverse reaction was the basis for recognizing tolerance to that food and introducing it permanently into the diet [19]. If there were adverse reactions, allergy was diagnosed after contact with a doctor. As the reactions were not severe, the parents repeated the administration of these foods after a few days to check its reproducibility.

The order of products introduced into the diet was changed as recommended by other researchers [8,20]. All parents used a modified dietary expansion method with their children. Pumpkin, broccoli, and cauliflower were served as first foods in a form of a watery mush (Table 4), followed by carrots, potatoes, green beans, zucchini, beets, and parsley. Vegetables with a high risk of causing an allergic reaction, such as sweet potatoes and green peas, were not given until after 6 months of age.


**Table 2.** Natural history of chronic food protein-induced enterocolitis syndrome (FPIES) dependent on cow's milk protein intake in the study group of children.

\* OFC—oral food challenge; \*\* 3 children dropped out of the study.

After 5 months of age, the diet was expanded by fruits such as peach, grapes, avocado, watermelon, and blueberries. Fruits more frequently causing allergic reactions, i.e., apple, pear, banana, and strawberries were introduced to the diet no sooner than after 6 months of age.

The greatest problems occurred with the supply of cereals, which are given at this age in a form of gruel or porridge. After 6 months of age, the supply of corn and wheat was suggested. Cereals, which in these children most often cause allergy symptoms, i.e., rice and oats, were introduced to the diet between 8 and 10 months of age.

Meat, fish, and egg were given at the same time as is recommended for healthy infants (Table 4). The order of supplying meat types was changed. Rabbit meat was recommended as the first meat, followed by pork and turkey meat. Beef and chicken were not introduced to the diet until the eighth month of age. Soya was not recommended until the twelfth month of age, nor was goat milk because of its high homology to cow's milk.

During the introduction of new foods into the infants' diet, allergy symptoms of IgE-independent allergy were observed (in response to some of the administered foods, despite the delayed time of their administration) (Table 3). Those were skin lesions and/or loose stools occurring from 8 to 24 h after consumption of the harmful food. They occurred in 6 children (11%) in response to 6 foods. The most common foods were: apple (3.6%), rice (3.6%), chicken, and turkey meat (1.8% each).


**Table 3.** Symptoms of allergy to new foods introduced into the diet in the study group of children with chronic food protein-induced enterocolitis syndrome (FPIES) dependent on cow's milk protein intake.

\* The provocation was performed twice; \*\* looked like atopic dermatitis but without itching.

**Table 4.** Introducing new foods to the diet in the study group of children with chronic food proteininduced enterocolitis syndrome (FPIES) dependent on cow's milk protein intake.

