Scarlet fever causes bright red rash, a high fever and a sore throat. It is still fairly common in children and there have been increasing outbreaks in recent years. According to the Centre for Health Protection, there are regular outbreaks in Hong Kong. Here is an expert-reviewed guide to scarlet fever, with paediatrician Dr. Eddie Cheung.
What is scarlet fever?
Also known as scarlatina, scarlet fever is generally a mild bacterial infection. It is commonly seen in children between 5 and 15 years old. Those younger than 10 are mostly affected and it is rare in children under 3. Fever and most symptoms usually subside within 24-48 hours after appropriate and prompt initiation of antibiotic treatment.
Scarlet fever is caused by Group A Streptococcus which is the same type of bacteria responsible for other common infectious diseases, such as impetigo and strep throat. The characteristic red bumpy rash of scarlet fever is a result of the toxins produced by the bacteria.
During diagnosis, your doctor will look at the rash. In most situations, only a clinical diagnosis is needed and treatment can be initiated afterwards. Throat swab for a rapid strep test +/- culture test may sometimes be done to confirm the diagnosis.
Your child will usually recover without having complications. They are infrequent and often the result of bacteria extending to infect other body areas. Complications include infections of the ear, sinus and the skin, pneumonia, rheumatic fever, kidney inflammation, arthritis and swelling in lymph nodes in the neck.
Scarlet fever is contagious and is a notifiable disease according to the Department of Health. Children may go back to school at least 24 hours after commencing antibiotics and when fever has subsided.
Incubation period: 2-5 days.
Infectious period: At least until 24 hours after initiation of antibiotic treatment. Up to 2-3 weeks after symptoms start if not on antibiotics.
How is scarlet fever transmitted?
The bacteria that causes the infection live in the mouth, throat and nose. Coughing and sneezing produces respiratory droplets that carry the bacteria. One can get scarlet fever by breathing in or touching things on which these droplets land.
Direct contact with the infected mouth and nasal secretions, and infected skin wound, or sharing foods, drinks and personal items with an infected person can also spread scarlet fever.
Signs and symptoms of scarlet fever
Children with scarlet fever often first present with a sore throat, fever and swollen lymph nodes in the neck. They may also have chills, headache, nausea, vomiting, body aches, abdominal pain and loss of appetite.
Pink-red rash usually develops after a day or two with the following characteristics:
- Rough or “sandpaper” texture due to the presence of numerous tiny bumps.
- Turning white or pale when pressed.
- Sunburn appearance.
- Beginning in the neck, armpits and groin, then spreading to the trunk and limbs, normally excluding the face, palms and soles.
- More marked rash in the underarms, elbows, groin and knees where the skin folds.
- Usually itchy.
- Skin peeling over several weeks when the rash fades after approximately 7 days.
Other distinctive signs are
- Strawberry tongue (red and bumpy tongue).
- Whitish or yellowish coating on the tongue.
- Red swollen tonsils and throat with white or yellow spots.
- Flushed face and a pale ring around the mouth.
When should you see a doctor?
Seek medical advice if you suspect that your child has scarlet fever, especially when they
- have a sore throat with fever, rash, swelling or pain in the neck glands.
- have just had chickenpox, impetigo or strep throat as one of the possible complications is scarlet fever.
- have been around someone infected with scarlet fever.
How is scarlet fever treated?
Antibiotics is the mainstay of treating scarlet fever if strep bacteria are found. Examples include amoxicillin and penicillin. For those who are allergic to penicillin, other antibiotics (e.g. erythromycin) will be given.
It is important to finish the entire course of antibiotics (usually 10 days) exactly as your doctor says, even if your child is getting better. It is to ensure that the bacteria is completely eliminated and to reduce risks of developing complications such as rheumatic fever.
There are a few ways you can do to help your child feel better:
- Drink plenty of fluids to stay hydrated.
- Keep your child’s fingernails short to avoid scratching.
- Make your child get enough rest for better immunity.
- Prepare soft or cold food for your child to soothe a sore throat, e.g. warm soups and ice popsicles.
- Make salt water for gargling to reduce pain and discomfort in the throat.
Currently, there is no vaccine to prevent scarlet fever. Here’s what you can do to protect your child from catching and avoid spreading the infection:
- Proper and frequent hand washing. Alcohol-based hand sanitisers are a good alternative if soap and water are not available.
- Covering nose and mouth while coughing or sneezing with a disposable tissue.
- Separating your child’s toothbrush, glasses, plates and dining utensils from other family members’. Wash them in hot water with soap.
- Not sharing food and drinks, baths, and personal items such as towels, clothes and bed linens.
- Keeping good ventilation.
Dr. Eddie Cheung 張蔚賢醫生 is a specialist in paediatrics. He received his paediatric training in Queen Mary Hospital and post-fellow paediatric cardiology training in Grantham Hospital/ Queen Mary Hospital. He is a Fellow of the Hong Kong College of Cardiology, the Vice President of Hong Kong Society of Paediatric Cardiology and Consultant of Hong Kong Association of Cleft Lip and Palate. He is currently working as Director of Paediatric Centre of HK Medical Consultants and serves as Infection Control Officer at the Hong Kong Adventist Hospital.