Fevers are a common symptom in children of all ages. "Webster's New World Dictionary" defines fever as "an abnormally increased body temperature." Normal temperatures range from 97 degrees Fahrenheit to 99 degrees Fahrenheit, according to the Mayo Clinic. The most accurate way to measure a child's temperature is by rectal thermometer.
Infection
The most common cause of fever in a child is infection. According to the Merck Manuals, the rise in body temperature is a response to substances called pyrogens that trigger the hypothalamus in the brain to raise the body's temperature. Microbes and their toxins are pyrogens that trigger the immune response and cause a fever. Fevers also help inhibit the growth of microorganisms inside the body, therefore helping in the immune response to infections. In children, viruses are the most common organism that produces fever. But other microbes, such as bacteria and fungi, can also trigger the brain to increase the body's temperature. Common infections that cause fever in children include ear infections, strep throat, colds, pneumonia and urinary tract infections.
Autoimmune Conditions
The Children's Hospital of Boston defines autoimmune disorders as conditions in which the body attacks its own tissues. This immune response can aim at a specific organ system or be widespread throughout the body. Fever is part of the autoimmune response in these illnesses. Unfortunately, the cause of most of these conditions is unknown. Some examples of autoimmune disorders in children include systemic lupus erythematosus, which presents with episodes of inflammation characterized by fever, butterfly rash on the face across the nasal bridge, joint inflammation, mouth ulcers and light sensitivity; juvenile arthritis, which presents with flareups of joint swelling and pain, fever, rash, swollen lymph nodes and fatigue; and vasculitis, a group of conditions characterized by fever and inflammation of blood vessels.
Cancer
Several childhood cancers can have fever as a symptom. The most common are leukemia and lymphoma. Leukemia is a cancer of the white blood cells, which fight infection. Lymphoma is a cancer of the lymph nodes. According to the Merck Manuals, fever in patients with lymphoma can indicate that the disease has spread throughout the body. But occasionally, especially with lymphoma, fever may be an early sign of the disease.
Immunizations
Vaccines are another common cause of fever in children. This occurs mostly with specific types of vaccines, for example, the measles, mumps and rubella, or MMR, vaccine; the vaccine against diphtheria, tetanus and acellular pertussis, or DTaP; and the pneumococcal vaccine. Fevers occur because vaccines stimulate the body's response to these microbes in order to protect the child from future infections. Fevers associated with immunizations are usually low-grade and are not a contraindication to future vaccination.
References
- Children's Hospital Boston: Autoimmune Diseases
- The Merck Manuals: Defenses Against Infection
- "Webster's New World Dictionary"; Michael Agnes; 2003
- Mayo Clinic: Fever: Causes
