Erythema Marginatum Due to Acute Rheumatic Fever - Causes, Symptoms, Diagnosis, and Treatment

What Is Erythema Marginatum?

Erythema marginatum is a rash that typically appears early in rheumatic fever. Have you ever noticed a faint, ring-shaped rash that appears suddenly and then fades away on its own? That’s often how this one behaves. These rings often have clear centers and slightly raised edges, giving them a “map-like” or wavy outline. The pattern can change quickly, fade in one area, and reappear in another.

Even though doctors consider it one of the main features of rheumatic fever, it is actually quite uncommon. In fact, fewer than six percent of people with rheumatic fever develop this rash.

What Is an Acute Rheumatic Fever?

Acute rheumatic fever is an inflammatory condition that can affect different parts of the body. It does not just cause a sore throat and go away; it can lead to swelling in the joints, brain, heart, and even the skin.

You might first notice joint pain. Or maybe unusual, involuntary body movements that seem hard to control. In some cases, the heart becomes inflamed, which is called carditis. Over time, this leads to heart failure, in which the heart cannot pump enough blood to the rest of the body. That is why early recognition and treatment are so important.

What Causes Erythema Marginatum in Rheumatic Fever?

The most frequent cause of erythema marginatum is rheumatic fever. But why does it happen? It usually starts after a group A Streptococcus (GAS) infection that wasn’t treated properly.

Sometimes, the body’s immune system reacts unusually after this infection. Instead of just fighting the bacteria, it becomes overactive and starts causing inflammation in different parts of the body, including the skin. That’s when the rash can appear.

Additionally, strep throat, Scarlet fever (a bacterial infection characterized by high fever and a sore throat), and impetigo (an itchy, painful skin condition) can be caused by GAS bacteria. However, the infection most frequently associated with rheumatic fever is strep throat. So if strep throat isn’t treated on time, it can further lead to rheumatic fever and, in some cases, erythema marginatum.

Who Is at Risk of Acute Rheumatic Fever?

Acute rheumatic fever does not affect everyone equally. Certain people are more at risk than others.

• Children and teenagers aged 5 to 15 are at the highest risk. It is uncommon in children under 5 and over 15.
• People who have had a recent untreated or poorly treated strep throat infection are also at higher risk. Without proper antibiotics, the chances of developing rheumatic fever increase.
• Those living in crowded conditions or areas with limited access to healthcare may be more vulnerable because strep infections can spread easily and may not be treated in time.
• A family history of rheumatic fever can also increase your risk of this infection.

What Are the Symptoms of Erythema Marginatum?

Erythema marginatum is a distinctive skin rash most commonly linked to rheumatic fever. It usually appears on the trunk and the upper parts of the arms and legs.

Symptoms include:

• Pink or light red ring-shaped rash.
• Clear center inside the rings.
• Wavy, snake-like borders.
• Flat or slightly raised edges.
• Rashes are non-itchy and painless.

The rash may become more noticeable with heat exposure, such as after exercise or a warm bath. When the rash fades, it may leave behind only a mild reduction in skin pigment.

Since erythema marginatum is usually associated with rheumatic fever, other symptoms of rheumatic fever may also be present, such as:

• Fever.
• Joint pain or swelling.
• Fatigue.
• Shortness of breath.
• Chest pain.

Because the rash is painless and temporary, it can be easily missed without careful examination.

How Is Erythema Marginatum Diagnosed?

When doctors are diagnosing erythema marginatum, they usually start with the basics: your medical history and a physical exam.

They will ask whether you recently had strep throat, because heart inflammation (carditis) linked to rheumatic fever often develops 2 to 5 weeks after a strep throat infection. The rash can appear before, after, or at the same time as heart symptoms.

During the exam, the doctor will carefully look at your skin. Sometimes the rash is harder to notice on darker skin tones, which can make diagnosis a bit more challenging.

If needed, doctors may order some tests, such as:

• Throat culture to check for Group A Streptococcus (GAS).
• Blood culture.
• Complete blood count (CBC).
• Skin biopsy.

If there are signs of heart involvement, your doctor may also recommend:

• Electrocardiogram (EKG/ECG) to check the heart’s electrical activity.
• An echocardiogram to show how the heart looks and functions.

Overall, the diagnosis is based on a combination of symptoms, medical history, physical findings, and lab tests to confirm the infection and assess for heart complications.

How Is Erythema Marginatum Treated?

When it comes to erythema marginatum, the rash itself does not need specific treatment. It usually fades on its own and does not leave permanent damage. Treating it does not change how the rash behaves.

Instead, doctors focus on treating the underlying cause, which is rheumatic fever triggered by a Group A Streptococcus (GAS) infection.

The first-line treatment is a long-term course of Penicillin to eliminate the Streptococcal bacteria and prevent complications. If someone is allergic to Penicillin, the doctor will prescribe another type of antibiotic from a different class.

What Complications Can Occur From Rheumatic Fever?

If rheumatic fever is not treated properly, it can cause serious problems, mainly affecting the heart.

Main Complications:

• Heart inflammation (carditis).
• Damaged heart valves.
• Chest pain.
• Shortness of breath.
• Irregular heartbeat.
• Heart failure (in severe cases).

Other possible complications include:

• Long-term joint problems.
• Uncontrolled body movements.
• Repeated episodes of rheumatic fever occur if strep infections are not treated.

How Can Rheumatic Fever Be Prevented?

Rheumatic fever can be prevented primarily by treating strep throat promptly and effectively.

If you or your child has a sore throat with fever, you should see a doctor. If it is caused by the Strep bacteria, the doctor will prescribe antibiotics. It is very important that you complete the full course of antibiotics, even if you start feeling better in a few days.

If you have had rheumatic fever before, your doctor may advise long-term preventive antibiotics to reduce the risk of recurrence.

You can also lower your risk by practicing good hygiene, such as washing your hands regularly, covering your mouth when coughing or sneezing, and not sharing utensils with others.

Conclusion

Erythema marginatum is an uncommon skin rash that can appear in people with acute rheumatic fever. Noticing this ring-shaped rash early and getting medical care can help doctors diagnose the underlying condition quickly and start treatment. Early care can lower the risk of long-term heart problems.

If you notice unusual skin changes along with fever or joint pain after a sore throat, it is always best to consult a skin care specialist promptly.

Key Takeaways

• Erythema marginatum is a rare, ring-shaped, painless rash linked to acute rheumatic fever.
• The rash itself is harmless, does not itch, and does not scar, but it signals an underlying autoimmune reaction that can affect the heart.
• Early treatment of strep throat can prevent rheumatic fever and its complications.