Erythema marginatum

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Erythema marginatum is a type of skin rash that is characterized by pink or red rings on the inner surfaces of the limbs and trunk. It is often associated with rheumatic fever and can be a sign of underlying cardiovascular disease.

Presentation

Erythema marginatum typically presents as non-itchy, pink or red rings that may appear on the arms, legs, and trunk. The rash can be transient, appearing and disappearing over the course of several weeks or months. The rings may have a clear center and can vary in size. The rash is usually not painful but can be a cause of cosmetic concern for patients.

Causes

The exact cause of erythema marginatum is not well understood, but it is commonly associated with rheumatic fever, which is a complication of streptococcal pharyngitis (strep throat). Rheumatic fever can lead to inflammation in various parts of the body, including the heart, joints, skin, and brain. Erythema marginatum is one of the major criteria for the diagnosis of rheumatic fever according to the Jones criteria.

Diagnosis

The diagnosis of erythema marginatum is primarily clinical, based on the appearance of the rash and its association with other symptoms of rheumatic fever. A thorough medical history and physical examination are essential. Additional tests may include throat cultures, antistreptolysin O (ASO) titers, and echocardiograms to assess for cardiac involvement.

Treatment

Treatment of erythema marginatum involves addressing the underlying cause, which is often rheumatic fever. This may include the use of antibiotics to eradicate the streptococcal infection, as well as anti-inflammatory medications such as aspirin or corticosteroids to reduce inflammation. Long-term prophylactic antibiotics may be recommended to prevent recurrence of rheumatic fever.

Prognosis

The prognosis for erythema marginatum is generally good, especially if the underlying rheumatic fever is treated promptly and effectively. The rash itself is not harmful and usually resolves without scarring. However, the long-term outcome depends on the extent of cardiac involvement and other complications of rheumatic fever.

See also

• Rheumatic fever
• Skin rash
• Streptococcal pharyngitis
• Jones criteria