Rheumatic Fever: A Case Of Mistaken Identity 

by Marcin Gornsiewicz, M.D.

A 7 year old becomes ill with fever and complains of joint pain in a knee. After a day or so, the knee gets better, but now the pain is in the ankle. The next day, the ankle is better, but now the elbow hurts. A pink rash appears on the legs. Several hours later it is gone, but returns the following morning. The fever persists. Her parent notices that the child is short of breath, and makes an appointment with the doctor. What could be wrong? After an examination and laboratory testing, the diagnosis becomes clear. This child has acute rheumatic fever (ARF), an inflammatory disease occurring after an untreated strep throat 3 weeks earlier. Sore throats are a common nuisance of childhood, but not all are alike. “Strep throat,” an infection caused by a bacteria called group A streptococcus, frequently causes fever, sore throat, swollen lymph glands, headache, and malaise. Untreated, it typically runs its course in a week or so. So, why is your child’s pediatrician so careful to treat your child with the appropriate antibiotic if strep throat is the diagnosis?Treatment with penicillin certainly shortens the duration of strep throat symptoms, but a more important reason to receive appropriate treatment is to prevent ARF. ARF is a potentially serious complication of untreated strep throat. While much less common today than prior to the antibiotic era, clinicians still see this disease in their practices. ARF occurs in about 2 people per year per 100,000 population in the U.S.. The figure in the developing world is about 19 per 100,000. Fortunately, less than 1% of untreated strep throats in the U.S. result in rheumatic fever.Should all sore  throats  be treated with antibiotics ‘just in case’? Definitely not….Inappropriate use of antibiotics can lead to development of antibiotic-resistant bacteria and other complications. Simply put, ARF appears to be a case of the body’s immune system causing damage to body tissues as it fights a strep throat. Researchers have determined that the molecular structure of certain body tissues bear a resemblance to the molecular structure of the streptococcal cell wall. In attacking the streptococcal bacteria, some cellular elements of the immune system may become confused and attack these body tissues as well, resulting in inflammation and damage. In this way, ARF is a case of mistaken identity. A patient with ARF is usually between 5 and 15 years old, and develops symptoms 2 to 4 weeks following a sore throat caused by group A streptococcus. Symptoms may include fever, rash (see photo), joint pain (typically moving from joint to joint and very responsive to aspirin), and shortness of breath or fatigue related to heart inflammation. If heart inflammation occurs it may result in damage to heart valves or heart muscle, which can worsen over time. Nervous system involvement results in “chorea,” or abrupt involuntary movements. These movements can be accompanied by weakness and emotional disturbances. Not all children with ARF develop all of the symptoms. The diagnosis can be difficult, and the severity of the disease varies from case to case. There is not a specific blood test for ARF, although physicians use laboratory testing to document that a streptococcal infection has occurred and that ongoing inflammation is present. Treatment is focused on eradicating the streptococcus from the body with antibiotics, reducing symptoms with anti-inflammatory medication, and preventing streptococcal infections in the future that would result in a relapse of the disease. A child that has had ARF should be treated with preventative antibiotics until adulthood to reduce the risk of subsequent strep infection (and relapse of rheumatic fever). Should all sore throats be treated with antibiotics “just in case”? Definitely not. Less than 30 percent of all sore throats are due to streptococcal infection. Inappropriate use of antibiotics can lead to development of antibiotic-resistant bacteria and other complications. How do I know if my child’s sore throat may be due to streptococcus? Several clues are:Throat pain that is severeFever higher than 100.4 degreesSwollen glands in the neckWhite patches in the back of the throatChildren fitting this profile should be evaluated by a health care provider. Appropriate treatment of strep throat will have your child feeling better sooner and will protect them from the potentially serious complications of rheumatic fever.Some or even all medications can be discontinued. However, more severe cases will require long-term treatment including drugs and physical therapy. It is important for children to be in good general health with an emphasis on diet, exercise and skin protection from ultraviolet light. Jay Warrick, M.D., is a board certified rheumatologist practicing in Knoxville since 1991. He earned a B.S. at Davidson College and his medical degree at East Carolina University. He completed residency and fellowship training at the Medical University of South Carolina. In addition to private practice, he assists in staffing a children’s rheumatology clinic at East Tennessee Children’s Hospital. For more information visit www.rheumatologyconsultants.org.