Evaluation and Management of Petechiae in Infants

Immediate Clinical Assessment

The American Academy of Pediatrics recommends assessing appearance and vital signs in infants with petechiae, as an ill-appearing infant with fever requires immediate parenteral antibiotics without waiting for test results, due to the risk of meningococcal disease progressing to purpura fulminans within hours 2, 3
The evaluation of petechiae distribution is crucial, as petechiae on the trunk, face, or ears in a non-cruising infant should raise concern for abusive head trauma and warrant careful examination for scalp bruising, bulging fontanel, subconjunctival hemorrhage, or oral injuries 4

A complete blood count (CBC) with differential and peripheral blood smear is the fundamental test to evaluate hemoglobin, white blood cell count, platelet count, and confirm true thrombocytopenia versus pseudothrombocytopenia, as recommended by the American College of Medical Genetics 1, 2
Peripheral smear review is critical for assessing platelet size, evaluating red and white cell morphology, and identifying schistocytes that may indicate thrombotic microangiopathy 1

The American Academy of Pediatrics advises against delaying antibiotics in ill-appearing infants with fever and petechiae while awaiting test results, as this can lead to severe consequences 2
It is essential to consider child abuse in the differential diagnosis, as petechiae on the trunk, face, or ears in a non-cruising infant warrant thorough evaluation for abusive head trauma, even if the physical examination is otherwise normal 4