Scarlet fever, or scarlatina, is a bacterial infection that causes a distinctive bright red sandpaper-like rash. Streptococcus pyogenes (group A strep)—the same bacteria responsible for strep throat—causes scarlet fever.
Scarlet fever was a serious and life-threatening condition in the past, but it’s now easily treatable with antibiotics. Without treatment, scarlet fever can lead to complications like rheumatic fever and affect the joints and major organs like the heart, kidneys, and brain.
Anyone can develop scarlet fever, but it most commonly affects children. Approximately 5 in 1,000 children in the United States develop scarlet fever each year.
Scarlet fever symptoms typically develop within a day or two after infection with group A strep bacteria and progress in stages. It usually begins with a sore throat and fever before a red, sandpaper-like rash appears.
Early Symptoms
The first signs of scarlet fever are similar to other bacterial and viral infections and may include:
- Fever of 101 degrees Fahrenheit (38.3 degrees Celsius) or higher, often with chills
- Sore throat and painful swallowing
- Headache
- Body aches
- Stomach pain
- Nausea
- Vomiting
Skin Symptoms
A red rash is the hallmark symptom of scarlet fever. It usually appears 1-2 days after the fever begins but can appear earlier or later. The rash:
- Starts on the neck, underarms, or groin before spreading across the body
- Initially appears as small, flat blotches before transitioning to tiny bumps that feel rough like sandpaper
- Appears brighter red in skin creases, such as the elbows, underarms, and groin
- Leaves a pale area around the mouth
- Fades after about a week, followed by peeling skin on the hands, feet, and groin
Throat and Mouth Symptoms
Scarlet fever also causes noticeable changes in the throat and tongue:
- White coating on the tongue (early symptom)
- Bright red and bumpy tongue, known as “strawberry tongue” (later symptom)
- Throat redness, with swollen tonsils and white patches or streaks of pus
- Petechiae (small red spots) on the roof of the mouth
- Swollen, tender lymph nodes (glands) in the front of the neck
Streptococcus pyogenes, or group A strep bacteria, causes scarlet fever. Scarlet fever occurs when these bacteria release harmful toxins into the body, leading to symptoms like a red rash and sore throat.
Group A strep bacteria live in the mouth and nose and spread through respiratory droplets when an infected person talks, coughs, or sneezes. You can also get sick by touching contaminated surfaces and then touching your face or sharing the same utensils, cups, or plates with someone infected. The bacteria is highly contagious and spreads quickly in close-contact environments like schools and daycare centers.
Risk Factors
People of all ages can get scarlet fever, but certain factors can raise the risk of infection, including:
- Age: Scarlet fever is most common in children aged 5-15.
- Spending time in crowded settings: Group A strep is highly contagious and spreads quickly in crowded settings, like schools, daycare centers, military training facilities, and homeless shelters.
- Recent strep infection: A recent strep throat or impetigo infection can develop into scarlet fever.
Healthcare providers diagnose scarlet fever by reviewing your symptoms and doing a physical exam. During the exam, your healthcare provider will look for the visible signs of scarlet fever, including a red, bumpy rash, a pale area around your mouth, a yellow-white coating on your tongue (in the early stages), or a bright red tongue (strawberry tongue).
Because other illnesses can cause similar symptoms, healthcare providers use diagnostic tests to confirm the presence of group A strep bacteria and rule out other conditions.
These tests include:
- Rapid antigen detection test (RADT): A rapid strep test involves swabbing your throat and testing the swab to check for group A strep bacteria. Results are ready within 15 minutes.
- Throat culture: Rapid strep test results are sometimes inaccurate, so your healthcare provider may order a throat culture to confirm the diagnosis. This involves swabbing the back of your throat and sending the swab to the lab. Results are usually ready after 2-3 days.
To treat scarlet fever, healthcare providers prescribe antibiotics, which kill the bacteria responsible for the infection. Most people start feeling better within a day or two of taking antibiotics, but it’s important to complete the entire course to eliminate all the infection-causing bacteria. Your healthcare provider may prescribe antibiotics such as:
- Penicillin: Oral capsules or liquid (taken by mouth) taken multiple times daily for 10 days
- Amoxicillin: Oral capsules or liquid, taken once or twice daily for 10 days
- Benzathine penicillin G: An intramuscular injection (shot) administered in one dose
If you have an allergy to penicillin or amoxicillin, your healthcare provider will prescribe different antibiotics, such as cephalexin, azithromycin, cefadroxil, or clarithromycin.
While antibiotics treat the infection, at-home measures can keep you comfortable and help reduce fever and soothe a sore throat:
- Take over-the-counter (OTC) pain relievers, such as Tylenol (acetaminophen) and Advil (ibuprofen)
- Gargle with warm salt water several times daily
- Drink warm herbal tea with honey
- Suck on throat lozenges
- Use a cool-mist humidifier or vaporizer
Scarlet fever spreads through respiratory droplets, so avoiding people who are sick and practicing good hygiene are the best ways to protect yourself from group A strep bacteria. To reduce the risk of scarlet fever:
- Wash hands frequently: Wash your hands regularly with soap and water for at least 20 seconds
- Avoid close contact with sick people: Avoid close contact with people with strep throat or scarlet fever, and don’t share utensils, cups, or personal items
- Cover coughs and sneezes: Use a tissue or elbow to prevent bacteria from spreading through the air
Although complications of scarlet fever are rare, they can occur if the bacteria spread to other body areas. Most complications are preventable by treating scarlet fever with antibiotics. Possible scarlet fever complications include:
- Rheumatic fever: An inflammatory disease that can develop weeks after infection, affecting the heart, joints, skin, and brain
- Post-streptococcal glomerulonephritis: An inflammatory kidney disease that can develop due to an immune response to group A strep bacteria, causing dark (red-brown) urine, decreased urination, swelling, and fatigue
- Ear infections: When bacteria spread to the middle ear, causing pain, fluid buildup, and hearing problems
- Pneumonia: Occurs when group A strep bacteria infect the lungs; happens in rare cases
- Abscesses: Abscesses (pockets of pus) around the tonsils caused by infections in the throat
Scarlet fever is a bacterial infection caused by Streptococcus pyogenes (group A strep). It primarily affects children and causes symptoms like fever, sore throat, and a red, sandpaper-like rash. Other symptoms include “strawberry tongue,” swollen lymph nodes, and peeling skin as the rash fades.
Antibiotics are the standard treatment for scarlet fever. You can lower your risk of scarlet fever by avoiding contact with people who are sick and washing your hands regularly.
Recognizing the symptoms of scarlet fever early and seeking medical care can ensure a quick recovery and reduce the risk of complications.
