Acute rheumatic fever, a disease that can cripple, cause severe heart damage and even death, virtually and mysteriously disappeared from the United States more than 20 years ago. Today the disease is making a comeback as mysterious as its disappearance.

"We are seeing an increase in the number of patients with rheumatic fever," says Dr. Larry Mahoney, professor of pediatric cardiology at the University of Iowa College of Medicine.

"Rheumatic fever is a complication of a streptococcal, or strep, infection of the throat. The fever is the body's delayed response to that infection," says Mahoney, also a staff physician at UI Hospitals and Clinics.

"Rheumatic fever occurs when body tissues are attacked by the immune system as if the tissues were foreign," he says. Symptoms include fever, swollen joints, chest pains or other signs of heart problems, including heart murmurs and congestive heart failure. "In a few cases, patients also develop a distinctive rash or small nodules under the skin and experience chorea, a purposeless, involuntary, rapid movement of the muscles."

The disease usually occurs in childhood and can cause long-term damage. It's a mystery why all cases of rheumatic fever occur after a sore throat that was caused by streptococcal bacteria, but only a few cases of strep throat lead to rheumatic fever.

"One of the best things a parent can do to help prevent their child from contracting rheumatic fever is to seek treatment for a strep throat infection," Mahoney says.

But how do you know which sore throat is a strep throat infection? Symptoms of strep throat include fever, headaches and swollen lymph nodes in the neck without nasal congestion or other symptoms associated with the common cold.

"The only way you can be certain a sore throat is a strep throat is to have your doctor perform a throat culture," Mahoney says. A throat culture is a sample of bacteria taken by swabbing the throat.

If your child is diagnosed with strep throat, the physician may prescribe oral antibiotics or give an antibiotic injection. If oral antibiotics are prescribed, be sure to give your child the full prescription, even if he or she begins feeling better. This will help guard your child from becoming infected with rheumatic fever.

Although rheumatic fever is not contagious, strep throat is. "If your child develops strep throat, keep him or her home from school so other children won't become infected," Mahoney suggests.

There is no vaccine for strep throat or rheumatic fever. Should your child develop rheumatic fever, your physician may prescribe antibiotics for an indefinite period of time. Your child will need continued medical care to monitor the disease. If strep throat recurs, rheumatic fever also can recur.