One reason for transient pale skin all over the body in a young infant is
bradycardia (slow heart beat). Is there any reason to suspect this baby may
have a heart defect, accounting for failure to thrive as well as transient
paleness? Or may simple bradycardia with no heart defect?
Kathy Dettwyler, writing from personal experience as the mother of a baby
who had bradycardia, not writing as a medical professional. Peter used to
turn as white as the sheet he was laying on.