What is a common finding in infants with polycythemia?

In infants with polycythemia, a common finding is deep red or purplish skin when crying. This condition is characterized by an increased number of red blood cells in the circulation, leading to a higher concentration of hemoglobin and a consequent rise in blood viscosity. During episodes of crying, increased blood flow can exacerbate the coloration of the skin, resulting in a deeper red or purplish hue. This is due to the increased volume of blood and the elevated levels of red blood cells, which affect the skin's appearance.

The other options present symptoms that are less characteristic of polycythemia. Pale skin coloration typically indicates anemia or reduced blood flow, which is not common in polycythemic infants. Decreased appetite can be associated with various conditions but is not a defining characteristic of polycythemia. Similarly, while abnormal heart rhythms can occur in many clinical scenarios, they are not specifically linked to polycythemia as a consistent finding.