Understanding the Roles of the Immune System in Cow’s Milk Allergy

Cow’s milk allergy (CMA) is one of the most commonly reported food allergies in infancy (Prescott et al. 2013). Incidence of CMA peaks during early childhood and tends to recede later, with the reported prevalence to be 0.6–2.5% in pre-schoolers, 0.3% in older children and teens, and less than 0.5% in adults (Fiocchi et al. 2010). A recent study performed in Europe supports these findings by demonstrating the overall incidence of challenge-proven CMA of 0.54% (Schoemaker et al. 2015). The self-perceived prevalence is unfortunately higher: 1–17.5% in pre-schoolers, 1–13.5% in older children and teens, and 1–4% in adults (Fiocchi et al. 2010; Jarvenpaa et al. 2014). This imposes dietary restriction on the CMA-suspected subjects, impairing the quality of life of both children and family, impeding children’s growth and causing unnecessary health care cost (Koletzko et al. 2012). The repetitive exposure to cow’s milk proteins in patients with persistent CMA could result in chronic allergic inflammation accompanied along with anatomical and physiological defects, such as eosinophilic gastroenteropathies (Galli et al. 2008; Leung et al. 2013). Of note is the phenomenon of atopic march, in which CMA patients (particularly the persistent cases) are having substantial risk to suffer from respiratory allergies, such as asthma, in their later life (Sprikkelman et al. 2000; Sampaio et al. 2005). It is therefore important to understand the CMA pathogenesis in order to correctly diagnose and to effectively prevent and manage the disease and its later life