Fever and vomiting are common symptoms of illness in children. Fevers are part of the body's immune system. They help fight off infections and stimulate microbe-fighting cells. Throwing up is also an indication of illness. Vomiting can lead to dehydration if the child is unable to tolerate fluids by mouth. Infections are the most common cause of fever and throwing up in children.
Gastroenteritis
Gastroenteritis is an infection of the gastrointestinal tract. In children, viruses and bacteria are the most frequent cause of infection. Common viruses include rotavirus, which, according to the National Digestive Diseases Information Clearinghouse is the leading cause of gastroenteritis among children between 3 and 15 months of age; adenovirus, which typically affects children under two years of age; and astrovirus, which affects infants and is most common during the winter months. Bacterial gastroenteritis is most commonly known as food poisoning. These bacteria infect children who eat undercooked meats or poorly handled fruits and vegetables. For example, salmonella can infect children who consume poorly cooked eggs or chicken; and E. coli affects those who eat undercooked meat. Children with gastroenteritis have fever, vomiting and diarrhea, which can be watery in viral infections and bloody if the infection is bacterial
Meningitis
Meningitis is an infection of the meninges, the tissue that covers the brain and the spinal cord. Symptoms of meningitis include fever, headache, vomiting, neck stiffness, irritability and changes in mental status, like lethargy and confusion. Bacteria and viruses are the most common microbes that cause meningitis. Viral meningitis is a mild illness that resolves on its own and only requires supportive care, like hydration and pain control. Bacterial meningitis is a potentially life-threatening infection that needs close medical attention and treatment with antibiotics and intravenous fluids.
Pneumonia
Children with pneumonia can also have fever and vomiting. The vomiting is usually post-tussive, or occurring after a coughing spell. This is more common in younger children. Other symptoms include cough and respiratory distress, with rapid and shallow breathing. Treatment includes fluids and oxygen, if needed. Children with bacterial pneumonia need antibiotic therapy,
Urinary tract infections
Urinary tract infections can also cause fever and vomiting. Mild fever reflects a milder infection, one affecting only the bladder. If the infection spreads to the kidneys, a condition called pyelonephritis, then a child can have high-grade fever with chills, nausea and vomiting and pain in the flank area, where the kidneys are located. According to Medline Plus, Urinary tract infections can be treated with oral antibiotics, but if the child is dehydrated, vomiting and unable to tolerate medicines by mouth, intravenous antibiotics are used to clear the infection.
