Recurring fevers occur at least three times in a six-month period. They might happen regularly or with no pattern at all, and they may or may not be accompanied by other symptoms. If your child has a recurring fever without the symptoms of a common illness, or if the fever is high or persistent, call your pediatrician.
PFAPA syndrome is the most common cause of recurring fevers in children, states the New Zealand Dermatological Society. PFAPA stand for the characteristic symptoms of the syndrome: periodic fever, aphthous stomatitis, pharyngitis and adenitis. Aphthous stomatitis causes small ulcers, or canker sores, in the mouth or on the genitals. Pharyngitis is inflammation of the tonsils, and adenitis is an inflammation of the lymph glands in the neck. Usually PFAPA syndrome begins in very young children; the mean age of first occurrence is 18 months. Treatment options include corticosteroids and other medications, and tonsillectomy.
Sometimes children experience recurring fevers from repeat infections. These may be viral, such as upper respiratory infections, the common cold or stomach viruses; or they can be bacterial, such as urinary tract infections, dental abscesses or sinusitis. These infections often, but not always, occur with other symptoms, such as nasal discharge and sore throat in the case of a cold or frequent urination and stomach pain in the case of a urinary tract infection. Because urinary tract infections, in particular, may cause no symptoms in young children, any baby or toddler with an unexplained fever should see a pediatrician for diagnosis.
Several autoinflammatory conditions can cause recurring fevers. Some are hereditary, and others occur without a family history. Some examples include familial Mediterranean fever, PAPA syndrome, juvenile idiopathic arthritis and Crohn's disease. Your child's doctor can diagnose these conditions by taking a careful medical history -- including a family medical history in the case of hereditary conditions -- blood and urine testing, and by noting symptoms associated with the recurrent fevers.
Parasites can cause recurring fevers that happen at irregular times. Epstein-Barr virus can, in some cases, cause a regularly recurring fever. Other potential health conditions that your doctor might evaluate your child for include lymphoma, central nervous system abnormalities and fevers as a side effect of certain medications. Many times, recurring fevers in children resolve on their own and don't require any medical care. Your child's doctor may advise a wait-and-see approach if blood tests come back normal to avoid additional testing.