[Clinical characteristics of children with IgE-mediated cow's milk protein allergy]

Objective: To analyze the clinical characteristics of children with IgE-mediated cow's milk protein allergy (CMPA) and provide a basis for disease management and prevention. Methods: A cross-sectional study was conducted to analyze 142 children aged 0-12 years who were diagnosed with IgE-mediated CMPA in Capital Institute of Pediatrics Affiliated Children's Hospital from 2020 to 2022. There were 79 males (55.6%) and 63 females (44.4%), with an average age of 14 (8, 27) months. 61 cases (43.0%) were in the <1-year-old group, 54 cases (38.0%) in the 1-3-year-old group, and 27 cases (19.0%) in the >3-year-old group. Data on demographic data, clinical manifestations, mean wheel diameter of skin prick test and serum specific IgE level were collected. The serum cow's milk protein sIgE and component sIgE were measured by ImmunoCAP fully automated system of fluorescence enzyme-linked immunosorbent assay, and statistically analyzed using chi-square test, nonparametric tests, correlation. Results: Cutaneous symptoms were the first and most frequent in 142 children (97.9%, 139/142 cases), followed by digestive (29.6%, 42/142 cases) and respiratory symptoms (27.5%, 39/142 cases).The proportion of children with respiratory symptoms after consuming cow's milk was significantly higher in the>3 years age group than those in the infant and toddler groups(66.7% vs 19.7%,χ18.396,P<0.01;66.7% vs 16.7%,χ=20.250,P<0.01), and the symptoms involving ≥3 systems were also significantly higher than those in the other two groups(37.0% vs 13.1%,χ=6.597,P<0.05;37.0% vs 7.4%,χ=12.120,P<0.01). The average cow's milk SPT diameter and serum sIgE levels in the>3 years age group were significantly higher than those in the infant and toddler groups (Z=-4.682, P<0.01; Z=-3.498, P<0.01); (Z=-4.463, P<0.01; Z=-6.463, P<0.01). The most common cow's milk component protein were β-lactoglobulin(65.1%,56/86 cases) and casein (57.0%, 49/86 cases). Multiple-sensitization rate of the patients were 54.9%. Egg white (43.7%, 62/142 cases) was the most common co-sensitization food allergen while mold (12.7%, 18/142 cases) and weed pollen (12.7%, 18/142 cases) were the main co-sensitization aeroallergens. The proportion of multiple-sensitization to aeroallergens in the children group was the highest (51.9%, 14/27 cases), followed by the toddler group (29.6%, 16/54 cases), and the infant group was the least (3.3%, 2/61 cases). There was a significant difference among these three groups (χ=7.476, P<0.05). Conclusion: Skin and mucosal symptoms are the most common in CMPA patients. The proportion of respiratory symptoms and multisystem involvement increased with age as well as the wheal diameter in skin test and serum sIgE level elevated. CMPA patients older than 3 years had the highest proportion of aeroallergen sensitization and airway allergic diseases.