A female baby born 2 weeks seems "purple"...

Question

A medical student working in the emergency department sees a female baby, born 2 weeks ago, who is brought in by her anxious mother. The mother tells the student that her baby seems “purple,” especially her fingers and toes, and looks extremely blue when crying. On physical examination the sleeping baby has mild cyanosis of the face and trunk, but moderate cyanosis of the extremities. Which of the following is the most common cause of cyanosis within the first few weeks of life?

(A) Atrial septal defect
(B) Patent ductus arteriosus
(C) Tetralogy of Fallot
(D) Transposition of the great vessels
(E) Ventricular septal defect

Answer 1

The correct answer is C.
Tetralogy of Fallot is the most common cause of cyanosis within the first few weeks of life. The skin becomes bluish because of the malformed right-to-left shunt. Infants also have worsening cyanosis with agitation, difficulty feeding, and failure to gain weight. Patients may also have clubbing of the fingers and toes or even polycythemia. The four components of the teratology are (1) ventricular septal defect, (2) overriding aorta, (3) infundibular pulmonary stenosis, and (4) right ventricular hypertrophy.