Originally Published: December 14, 2001 - Last Updated / Reviewed On: January 7, 2015
I have a case of scarlet fever and was wondering how contagious it is and for how long. Am I putting people at risk by being around them?
It's very kind of you to consider the contagious factor! Scarlet fever is a bacteria that is spread by inhaling the droplets of an infected person (released for example, during coughing), by sharing utensils or other personal items, or by direct contact with an infected person. Effective hand washing is a great prevention tool. It’s worth noting that your level of contagiousness drops considerably after being on antibiotics for 24 hours. At that time, it is unlikely that you could spread the infection to another.
Here’s some background: scarlet fever is a disease caused by group A streptococcus — the same bug responsible for strep throat. Scarlet fever usually occurs in children 5 to 15 years old. Symptoms usually develop within two days of becoming infected and may include:
- A reddish-pink rash that spreads from the neck and face to the rest of the body (often described as having a rough, sandpapery feel and peels as it begins to fade)
- "Strawberry tongue" that's red, swollen, and has a white coating early on
- Bright red lines in the skin of the underarms and groin and around the mouth
- A very red and sore throat
- Difficulty swallowing
- Fever and chills
- Abdominal pain
- General body aches
Your health care provider can diagnose scarlet fever during a physical exam (the rough rash is a dead giveaway) and via a throat culture. If left untreated, the bacteria can spread to other parts of the body, including the lungs, kidneys, tonsils, blood, and middle ear. In rare cases, it can also develop into rheumatic fever.
A variety of different antibiotics can treat group A strep and the illness subsides rather quickly once treatment begins, though the rash can hang around for seven days or longer after a person begins antibiotics. Even if you’re feeling better, take your full course of antibiotics to prevent any resistant bacteria from proliferating. While it’s good to be cautious about potential transmission, feel free to lift the quarantine 24 hours after beginning your antibiotic treatment unless your health care provider instructs you otherwise.
Here’s to feeling better soon,