The Cow's Milk‐Related Symptom Score ( <scp>CoMiSS</scp> ) in Presumed Healthy Mexican Infants

The Cow's Milk-related Symptom Score (CoMiSS) was developed as an awareness tool for healthcare professionals regarding the possibility that the combination of symptoms might be caused by cow's milk allergy (CMA) [1]. The primary aim of this report is to report the CoMiSS in 106 presumed healthy Mexican infants and to compare these findings with the CoMiSS in other populations of presumed healthy infants from Europe, Egypt and Brazil and Indonesia [2-5]. The CoMiSS collects information on (i) the frequency and severity of regurgitation, (ii) stool consistency according to the Brussels Infants and Toddlers Stool Scale (BITTS), (iii) duration of crying, (iv) skin manifestations such as atopic dermatitis, urticaria and angio-oedema, (v) respiratory tract symptoms (runny nose, coughing) [1]. Each symptom has a maximum weight of 6, except for the respiratory symptoms (maximum of 3). The score varies between 0 and 33 as maximum. A score of ≥ 10 should raise awareness about the possibility that CMA might be the cause of the combination of the symptomatology, while a score < 6 makes the diagnosis of CMA very unlikely [1]. As a consequence, CoMiSS will decrease during a diagnostic elimination diet in the suspected diagnosis of CMA is correct, but obviously the score will not decrease to 0 since many healthy infants present some of the manifestations listed in CoMiSS. Therefore, in order to evaluate the efficacy of a diagnostic elimination diet, it is important to determine CoMiSS values in a presumed healthy population. However, normal data in European infants have shown variability amongst countries for some of the subscores, notably for crying [2]. Therefore, it is important to determine the normal range of CoMiSS in different parts of the world. Up to now CoMiSS in presumed healthy infants have been published in European, Egyptian, Indonesian and Brazilian infants (Table 1) [2-5]. In this paper we report CoMiSS in 106 (46.2% male) presumed healthy Mexican infants (age range 1–11 months; mean 2.8 months) from Mexico City, evaluated at one single centre (Hospital Infantil Privado) (Table 1). Only infants from native born Mexican parents were included. Exclusion criteria were (i) parents with different ethnicity, (ii) prematurity (< 37 weeks gestation at birth); (iii) known or suspected diseases; (iv) infants seeking medical consultation due to symptoms, including related to CMA; (v) infants using medication, therapeutic formula or food supplements other than the recommended vitamins. The CoMiSS was completed by the consulted health care professional (as was the case in the different infant populations). We obtained ethical approval from the corresponding ethical committees, including the Ethical Committee of the UZ Brussels. There was no funding for this study. Classic descriptive statistics were done, the testing of significant differences in proportions was done using a chi square test and in continuous variables using a t-test or Mann Whitney U test depending on the underlying distribution of the data. The median (Q1;Q3) CoMiSS was 2 (0;6). The 95th centile was 11. Overall, the CoMiSS values in presumed healthy Mexican infants are within the ranges reported for European, Egyptian, Indonesian and Brazilian presumed healthy infants [2-5]. In the Mexican data, there was no significant difference according to sex (p = 0.101), exclusive breastfeeding vs. mixed or full formula feeding (p = 0.105). There was no significant difference in CoMiSS in the 0–6 vs. 6–12 months old group (p = 0.706). Only when comparing the respiratory score in the 0–6 and 6–12 months old groups a significant difference was noticed (p = 0.031). Slight and mild respiratory symptoms were more frequent in the 6–12 months old group (18% vs. 2%). Overall, the Mexican data were quite comparable with the Brazilian ones [5]. Median CoMiSS was lower in the Indonesian infants than in the other populations. This difference is mainly related to a difference in reported stool consistency [2-5]. This difference in stool consistency might be true, but it cannot be excluded that the difference in consistency might be the consequence of a different interpretation of an identical stool consistency. Therefore, the development of a more objective convolutional neural networks algorithm to determine stool consistency may result in more reliable data [6]. Overall, CoMiSS has been determined in 2695 presumed healthy infants from representing different European countries, North Africa, South Asia, Central and South America. Although there are no striking differences, it would be worthwhile to collect additional data from China, Central Africa and North America. If all the collected data are pooled together, it will be possible to develop percentile curves of CoMiSS, including severity of regurgitation and duration of crying in presumed healthy infants. This data might then help health care professionals to inform parents about the normality of these conditions in healthy infants. CoMiSS can contribute to reassure parents about the normality of manifestations such as crying and regurgitation in infants. Erick Manuel Toro Monjaraz: investigation, methodology, writing – review and editing. Clara Aurora Zamorano-Jimenze: investigation, writing – review and editing, methodology. Nienke Knockaert: writing – review and editing, formal analysis. Koen Huysentruyt: project administration, writing – review and editing, software, conceptualization, formal analysis. Yvan Vandenplas: conceptualization, writing – original draft, writing – review and editing, methodology, formal analysis, project administration, supervision. YV: clinical investigator for Danone, nestle Health Science, Nestle Nutrition Institute, Nutricia, United Pharmaceuticals (Novalac); advisory board member for Abbott Nutrition, Alba Health, Arla, Biogaia, Danone, ELSE Nutrition, Friesland Campina, Nestle Health Science, Nestle Nutrition Institute, Nutricia, Pileje, United Pharmaceuticals (Novalac); speaker for Abbott Nutrition, Arla, Biogaia, Danone, Friesland Campina, Nestle Health Science, Nestle Nutrition Institute, Nutricia, United Pharmaceuticals (Novalac). The other authors report no potential COI.