METHODOLOGY
This is an observational and descriptive study in infants under 1 year of age who attend a private allergic disease care center for CMPA evaluation during the year of 2021. The study included all children from 0 to 12 months who were treated at the center. Considering the expected frequency of 3.5% of CMPA for children under 1 year of age, an acceptable margin of error of 10%, with a level of confidence of 90%, we estimated a sample of 64 patients. Calculations were performed using Epi Info software. To compare FC and EDN values based on symptoms, the Mann Whitney U test was used. Inclusion criteria were: patients 0 to 12 months of age with a diagnosis of IgE - mediated or non – IgE - mediated CMPA based on clinical evaluation by a physician taking into account the following criteria:
For IgE - mediated CMPA: Immediate allergic symptoms during a double – blind – placebo – controlled food challenge (DBPCFC) or history of immediate allergic symptoms after exposure to cow’s milk or products containing cow’s milk proteins with a specific IgE level ≥ 5 kUA/L for children ≤ 1 year; or prick test with a papule ≥ 6 mm.
For non - IgE mediated CMPA: Predominantly diarrhea: change in stool consistency to type 6 and type 7 of the Bristol scale during DBPCFC. Predominantly reflux: based on the Vandenplas reflux score corresponding to a score of 3 during DBPCFC. Predominantly constipation: change in stool consistency to Bristol type 1 and 2 during DBPCFC. Predominantly colic: crying > 3 hours/day at least 3 times in a week for 1 week during DBPCFC (6). Presentation of Protein - Induced Enterocolitis: 2 reactions of typical symptoms by clinical history or by DBPCFC based on diagnostic protocol (7).
The exclusion criteria of the study were: coexistence of congenital, metabolic or genetic disorders, malformations, primary immunodeficiencies. Through a data collection form, information related to demographic characteristics, family history of atopy, clinical manifestations, and causality with food exposure was obtained. Likewise, all patients with suspected IgE - mediated CMPA underwent a skin prick test and ImmunoCAP for cow’s milk protein, and all patients with non – IgE -mediated CMPA underwent FC and EDN tests. After 1 year of diagnosis patients underwent to DBPCFC and observed 1 week in order to know if they acquired tolerance to cow´s milk proteins or not. We describe the hypoallergenic formula patients used and if they presented any adverse events during 1 year of observation. The study was submitted to the Ethics Committee of the National Children´s Intitute – Breña/ Instituto nacional de Salud del Niño – Breña, and before starting the study the parents of the children signed an informed consent.