Cough receptors hypersensitivity syndrome: the cough that makes cough

Key words: Cough, SIRT, Cough Receptor Hypersensitivity Syndrome, Children

Dry cough usually accompanies the first few days of each “cold” (Upper Respiratory Tract Infection: URTI), but in some children, it always recurs with a particular intensity that “prevents sleep” and puts the whole family to the test. This cough is recognized to have an etiopathogenetic factor of an exaggerated sensitivity of cough sensory receptors. In the year 2000, the “Medico e Bambino” journal coined the acronym SIRT (Sindrome da Ipersensibilità dei recettori della Tosse - Cough Receptors Hypersensitivity Syndrome) to label this phenotype of cough. Today, this diagnosis is made more frequently especially by Italian family paediatricians who have learned to understand and recognize it. However, in the paediatric literature, SIRT still lacks recognition and an adequate description of its peculiar clinical characteristics. It is conceivable that SIRT corresponds to the persistent cough during the most acute phase of URTIs. The mechanisms by which viral infections induce the dysregulation of the cough reflex are now well understood, but why it remains unchanged over time in only certain individuals is still unknown. In adulthood, cough due to cough receptor hypersensitivity (Cough Receptor Hypersensitivity, CRH) has received much more attention, becoming an “umbrella” diagnosis for all “chronic” coughs of undefined cause. CRH recognizes the same mechanisms and causes at all ages, but there is a significant clinical difference that, in children, due to the high frequency of URTIs, it is characterized by recurrent episodes of acute cough, while in adults, CRH primarily manifests as a “chronic” cough induced by micro environmental stimuli (thermal, mechanical, chemical).