Patient's question:
My baby's fontanelle is bulging and jumping. My family says it's the baby's soft spot. How can I determine if the baby's fontanelle is sunken?Doctor's answer:
Normal infants have a flat anterior fontanelle. At birth, the length of the line connecting the midpoints of the opposite sides of the anterior fontanelle is 1.5 to 2 centimeters. It gradually ossifies and decreases in size over the next 6 months, and in most infants, it closes between 1 and 1.5 years of age.Infants with a large anterior fontanelle may have cranial ossification disorders or systemic diseases. A small anterior fontanelle is commonly seen in microcephaly, often closing between 1 to 3 months of age, which can affect brain development.
A bulging anterior fontanelle is often associated with increased intracranial pressure due to various causes and is an important sign of infantile meningitis or encephalitis. A sunken anterior fontanelle is more common in infants with acute gastroenteritis or dehydration caused by vomiting and diarrhea.