Streptococcus : Rheumatic Fever, Skin Infection, Kidney Disease

by Food and Drug Administration (FDA)

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Rheumatic Fever

Lurking behind several types of strep infections is the possibility of rheumatic fever. Although a relatively uncommon disease, the effects of rheumatic fever are serious enough to warrant concern. Signs of rheumatic fever include a red rash, pea-sized lumps under the skin, tender joints, fever, involuntary jerky movements, heart palpitations, chest pain, and, in severe cases, heart failure. Although most symptoms disappear within weeks to months, about half the time the disease leaves behind deformed heart valves that may limit patients' physical activities and foster premature death from heart failure.

Diagnosis of rheumatic fever is based on its symptoms in conjunction with a history of a recent strep infection, which can be confirmed by tests for strep antibodies in the blood.

Rheumatic fever is thought to be triggered by an overly active immune system, which inadvertently destroys body tissues in its zeal to rid the body of a strep infection. Most symptoms of rheumatic fever crop up one to four weeks after a strep infection, although involuntary jerky movements may not surface for as long as six months after infection. About half of the recent cases of rheumatic fever, however, developed with mild to no previous signs of a strep throat infection, such as a sore throat with fever.

It's these signs of a strep infection that physicians rely on to prevent rheumatic fever. As many as 3 percent of untreated cases of strep throat can develop into rheumatic fever. But antibiotic treatment, even if it's not started until several days after the onset of symptoms, can squelch the possibility of rheumatic fever.

Once rheumatic fever occurs, doctors can do little to prevent its damage in the body. Anti-inflammatory drugs (such as aspirin or steroids) can ease many of the symptoms and possibly prevent some of rheumatic fever's more serious developments. Antibiotics are also used to treat any lingering strep infections. But even with such therapies, the disease often wreaks such damage on heart valves that they have to be surgically repaired or replaced with synthetic or animal implants.

Rheumatic fever usually recurs whenever its victims experience any new strep infections. To prevent such flare-ups, the American Heart Association recommends that anyone who has experienced rheumatic fever take prophylactic (preventive) doses of antibiotics. How long rheumatic fever patients require such a preventive drug regime depends on whether they experienced heart damage and whether they're likely to develop a future strep infection. Children who've had rheumatic fever, for example, generally take antibiotics on a daily basis until they reach adulthood, when the risk of a strep infection greatly diminishes.

Skin Infection

When Group A streptococci literally get under the skin, they can foster a common skin disease known as impetigo. This contagious disease frequently afflicts mainly children during the summer, when insect bites, cuts and scrapes are prevalent. These skin infringements serve as portals of entry for the streptococci.

Impetigo starts out as a rash of pinhead-sized blisters or pimples that rapidly run together to form yellow, flaky crusts. The impetigo rash may itch or burn, but rarely causes pain. The disease is diagnosed with the aid of cultures of the fluid lodged beneath the crusts. If large numbers of strep bacteria crop up in these cultures, their guilt in causing the disease is firmly established. Impetigo can also be caused by other bacteria, including Staphylococcus, or by mixtures of staphylococcal and streptococcal bacteria.

Impetigo is combated with the use of topical or oral antibiotics, depending on its severity and frequency within a given population. Doctors advise impetigo patients to remove the skin crusts and wash their rash with soap on a regular basis. Occasionally, if not treated, streptococcal impetigo develops into a blood infection, and it can also foster kidney disease.

Kidney Disease

All kinds of strep infections can foster an inflammation of the kidneys (acute glomerulonephritis), although the disease most often follows impetigo. Less than 1 percent of all strep infections foster kidney disease, but because certain strains of strep are particularly prone to causing this complication, small epidemics of acute glomerulonephritis can crop up in private homes or in schools.

Symptoms of the disorder include a puffy face due to water retention, blood in the urine, pain in the loins, malaise, nausea, headache, and high blood pressure. These symptoms usually surface one to three weeks following a strep infection and subside within the same amount of time.

Diagnosis of acute post-streptococcal glomerulonephritis is based on symptoms, a history of a recent strep infection, and elevated levels of antibodies to strep in the blood. This form of kidney disease, like rheumatic fever, is thought to stem from an overactive immune response to strep.

Little can be done to prevent this heightened immune response once it's begun, although various drugs (such as diuretics) and dietary measures (such as restricted salt or protein intake) can ease many of its symptoms. Most patients recover without any permanent problems, although occasionally kidney damage inflicted by the disease may require dialysis or a kidney transplant.

Patients rarely experience a recurrence of acute glomerulonephritis following additional strep infections because of the immunity they develop to the specific type of strep bacterium that caused their disorder. (Only a handful of strep types can cause glomerulonephritis, and most cases of the disorder can be traced to a specific Group A streptococcal strain known as Type 12.)

About the Author

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