Scarlet Fever

Overview

By Tina Shahian, PhD

Scarlet fever, also called scarlatina, is a bacterial infection caused by the Streptococcus bacteria (group A strep, or GAS) – the same bacteria that causes strep throat. It is generally accompanied by a sore throat, a high fever and a signature red rash that is rough to the touch and covers the body. It affects a small fraction of people who already have strep throat. In rare cases, the disease affects individuals with a streptococcal skin infection. Scarlet fever is most common in children between the ages of 5 and 12, but it can affect people of all ages. Timely treatment with antibiotics allows quicker recovery, reduces spread to others, and lowers the risk of developing rare, but serious, long-term complications.

Causes and Risk Factors

Streptococcus bacteria in a CDC photomicrograph, 900x magScarlet fever is caused by Streptococcus (group A strep) bacteria, which causes strep throat. When the bacteria release toxins in the body, the characteristic red rash results. The bacteria primarily spread when an infected person sneezes or coughs, and passes the bacteria through liquid droplets in their nose or mouth. Infected droplets on the surface of shared dishes and utensils may also cause transmission. Touching the open sores on the skin of a person with streptococcal skin infection can also transmit the bacteria.

Following exposure, it takes 2-4 days until the onset of symptoms. The biggest risk factor for scarlet fever is being infected with the Streptococcus bacteria. Children are at highest risk, especially in community settings such as schools and childcare centers.

Symptoms

The first symptoms of scarlet fever are a high fever and sore throat. After 1-2 days, a red rash that mimics a sunburn and feels rough like sandpaper develops on the body. It may start on the face, neck, underarms or groin areas before spreading to the rest of the body. The rash slowly fades over the course of a week. The full list of symptoms include:

  • A high fever of 101° F or more
  • A red, sore throat 
  • A red rash that feels rough to the touch
  • A bright red color on the armpits, groin or elbows
  • A red tongue (strawberry tongue)
  • A flushed face with a pale ring around the mouth
  • A white coat over the tongue or throat
  • Swollen glands
  • Headache
  • Body ache and chills
  • Nausea and vomiting
  • Difficulty swallowing (due to sore throat).

Diagnosis and Treatment

strawberry tongue from scarlet feverDoctors diagnose scarlet fever by doing a physical exam and looking at the back of the throat. To confirm strep throat, a throat swab culture test is performed to look for the Streptococcus bacteria. This is essential for matching the infection with the right treatment.

Scarlet fever is treated with a course of antibiotics that kill the bacteria. The infection clears up within days while the rash fades over the course of weeks. As the rash fades, peeling can occur around the fingers, toes and groin areas. If left untreated, scarlet fever is a risk factor for serious long-term health complications, including:

Prevention

The best way to prevent scarlet fever is by frequent handwashing and avoiding contact with infected individuals.

Sources

  • “Scarlet fever”. MedlinePlus, NIH. Retrieved Aug 17, 2015. http://www.nlm.nih.gov/medlineplus/ency/article/000974.htm.
  • "Scarlet fever". Mayo Clinic. Mayo Foundation for Medical Education and Research. Retrieved Aug 17, 2015. http://www.mayoclinic.org/diseases-conditions/scarlet-fever/basics/definition/con-20030976.
  • “Scarlet Fever: A Group A Streptococcal Infection”. Centers for Disease Control and Prevention (CDC). Retrieved Aug 17, 2015. http://www.cdc.gov/features/scarletfever/.