Transferrin saturation is a calculated value resulting from a medical laboratory test to measure the amount of iron bound to transferrin in the blood. The liver produces transferrin, which is a protein that serves to bind iron molecules and carry them through the bloodstream to the bone marrow.
In addition to the cough, your child may also have a hoarse voice and have laboured breathing. Croup is most common in autumn and winter, and when a child is between 6 months and 3 years old. However, older children up to 15 years old sometimes get croup too. Croup is a common respiratory condition in children caused by either a viral infection or allergy.
1 Croup is rarely seen in adults because their larger breathing passages (trachea and larynx) can accommodate the inflammation without producing symptoms.  Some children appear to be particularly prone to croup and have a number of infections.