Some common symptoms of neonatal pneumonia include: frothy sputum, shortness of breath, cough, fever, and the three-concave sign. If the bacterial pathogen of this lung infection also affects the gastrointestinal tract, there may also be symptoms of vomiting and diarrhea. When severe pneumonia causes cyanosis and lack of oxygen in the child, accompanied by frequent vomiting and diarrhea, leading to dehydration, this type of pneumonia is quite severe and it is essential to seek timely medical treatment at a hospital.