Beyond strep throat: Understanding scarlet fever and rheumatic fever

Many people think scarlet fever and rheumatic fever are illnesses from long ago—serious conditions we only read about in classic books or see in historical dramas. But the truth is, while rare, these complications from strep throat still occur today and can have serious consequences if not treated promptly.

Most sore throats are harmless. But when caused by group A streptococcus (the bacteria behind strep throat), they can lead to more serious health problems,  if left untreated.

Let’s break down the warning signs, risks and how to protect your child.

Scarlet fever: The rash that follows strep

Scarlet fever is a bacterial illness that sometimes follows strep throat, caused by toxins released by the streptococcus bacteria. While it mostly affects children ages 5 to 15, adults can get scarlet fever too.

Common symptoms

• Bright red, sandpaper-like rash (usually starting on the chest and spreading)
• Red lines in body folds (look under the arms or in the groin)
• A flushed face with a pale ring around the mouth
• High fever and sore throat
• “Strawberry tongue” (red and bumpy)

Complications
When treated with antibiotics, scarlet fever usually clears up without complications. But untreated, it can lead to a number of issues, including:

• Ear infections
• Pneumonia
• Rheumatic fever
• Kidney disease

Scarlet fever can easily pass from person to person, so quickly addressing symptoms is key.

Rheumatic fever: A threat to the heart

Rheumatic fever is an autoimmune reaction that can happen weeks after an untreated or under-treated strep throat or scarlet fever. The body’s immune system, trying to fight the strep bacteria, mistakenly attacks healthy tissues, including the heart.

While rheumatic fever is rare in the U.S., it’s more common in areas with limited access to health care. Children ages 5 to 15 are most affected.

Common symptoms

• Fever and fatigue
• Painful, swollen joints (often moving from joint to joint)
• Chest pain or palpitations
• Shortness of breath
• Skin rash or small lumps under the skin (nodules)
• Uncontrolled body movements (Sydenham chorea)

Complications
Rheumatic fever can cause permanent damage to the heart, especially the valves, a condition called rheumatic heart disease. It can also lead to heart failure later in life. Unlike scarlet fever, rheumatic fever is not contagious.

Prevention starts with early treatment

The best defense against scarlet fever and rheumatic fever is simple: treat strep throat early with a full course of antibiotics.

See a doctor if your child has:

• A sore throat with fever or swollen tonsils
• A rash that looks like sunburn or sandpaper
• Joint pain or strange movements following a recent illness

With timely treatment, scarlet fever is easily managed and rheumatic fever can often be prevented altogether. But both conditions highlight the importance of not brushing off a strep infection as “just a sore throat.”

Need care?
SIU Medicine offers pediatric and family medicine providers who can diagnose strep throat quickly and help your child feel better fast. Visit [siumed.org] or call [clinic number] to schedule an appointment.