Pediatría, síndrome de Down y patología alérgica

Allergic diseases have a genetic basis (atopy), meaning that inheritance is a determining factor in the development of these processes. Respiratory pathologies are the most common, although reactions to foods and drugs also occur. The most common clinical manifestations occur in the skin and digestive tract, and generalised reactions (anaphylaxis) can often occur that can be severe or even fatal. The increase in respiratory pathologies in recent years has been linked to a reduction in infectious diseases in developed countries. The activity of Th1/Th2 lymphocytes has become imbalanced, leaning towards the Th2 that are responsible for producing antibodies against allergens (“hygiene hypothesis”). In spite of this, children with trisomy 21, with the wide gamut of altered genes responsible for many of the processes associated with this syndrome, rarely suffer from allergic diseases. This is reflected in the small number of publications on this field. In contrast, immune response to pathogens is constantly affected (greater incidence of infections requiring the production of specific antibodies produced by Th1 lymphocyte activity) along with other processes (auto-immune, leukaemia) related to patient immunity, and this could be the cause of the reduced possibility for allergic reactions.