In general, a child’s fontanelle should be flat to the touch with little tension. Especially if the fontanelle does not bulge when the child sits up, but it bulges or has some tension when the child sits up, it means that there may be an increase in intracranial pressure. If the fontanelle bulges and there are clinical symptoms, we should think about the possibility of central infection. Because children at this age have poor resistance and atypical clinical manifestations, the bulging fontanelle is an important sign to detect the possibility of central infection in children at an early stage, and if necessary, lumbar puncture may be done to assist in the diagnosis. Vitamin A toxicity can also sometimes cause bulging fontanelle, so sometimes clinical analysis is needed, and not every child with this condition has a central infection.