Scarlet fever in Adult
Alerts and Notices
SynopsisScarlet fever is an acute toxin-mediated disease caused by infection with group A beta-hemolytic streptococci (Streptococcus pyogenes). Most cases follow a streptococcal pharyngitis or tonsillitis. However, streptococcal sepsis, cellulitis, puerperal infection, or surgical infection can initiate scarlet fever. Scarlet fever is most common in children younger than 10 years, but it can affect adults as well.
A 2-5 day incubation period precedes the onset of rash. Associated prodromal symptoms include fever and malaise. Sore throat and swollen, tender anterior cervical lymph nodes are typical. Abdominal pain, nausea, and vomiting are common in younger children. Petechiae may be present on the soft palate.
The characteristic rash begins within 12-48 hours of fever onset. It initially presents on the trunk and spreads to involve the extremities, sparing the palms and soles. The rash is often accentuated in flexural creases. It manifests as confluent tiny, erythematous papules with a "sandpaper-like" appearance. Enlarged tongue papillae may give the appearance of a "strawberry tongue." The rash tends to fade in a week and is followed by desquamation.
Once a fatal disease in the pre-antibiotic era, scarlet fever's associated complications are now fortunately rare with the existence of effective antibiotic therapy. However, meningitis, otitis, sinusitis, pneumonia, arthritis, rheumatic fever, and glomerulonephritis can still rarely occur as in any streptococcal infection.
In 2022-2023, the United Kingdom reported a surge in scarlet fever that coincided with an increase in invasive S pyogenes (invasive group A strep [iGAS]) infections. In the United States and elsewhere in Europe, iGAS infections in children, including necrotizing fasciitis and streptococcal toxic shock syndrome, have increased without a concomitant increase in cases of scarlet fever.
A38.9 – Scarlet fever, uncomplicated
30242009 – Scarlet fever
Differential Diagnosis & Pitfalls
- Toxic shock syndrome originates from Staphylococcus aureus infections arising in the setting of super-absorbent tampons, nasal packing, or surgical site infections. Patients are systemically ill and eventually desquamate.
- Staphylococcal scalded skin syndrome (SSSS) usually occurs in young children following an S aureus infection. The affected skin is notably tender.
- Kawasaki disease is characterized by strawberry tongue, conjunctival injection, cervical lymphadenopathy, and rash. This is also more common in children.
- Exanthematous drug eruptions will have a history of exposure.
- Viral exanthems (such as roseola or coxsackie virus, among others).
- Sunburns occur after sun exposure and are photodistributed.
- Photosensitive and phototoxic drug eruptions are photodistributed.
- Photocontact dermatitis is photodistributed.
- Rubeola has associated cough, coryza, conjunctivitis, and Koplik spots.
- Rubella has occipital and postauricular lymphadenopathy.
- Rat-bite fever
- Infectious mononucleosis has associated lymphadenopathy.
- Primary human immunodeficiency virus (HIV) infection is characterized by lymphadenopathy and rash.
- Lupus erythematosus has associated photosensitivity.
Patient Information for Scarlet fever in Adult
OverviewScarlet fever is an infection with a type of bacteria called Streptococcus, which not only causes a throat infection ("strep throat"), but also produces a poison (toxin) causing the distinctive rash of scarlet fever. Some people are more sensitive to the toxin than others, so not everyone in a family who is infected will have the rash, even if they have the throat infection. Sometimes the area of infection is the skin rather than the throat, a condition called impetigo.
Scarlet fever is contagious to people who come into close contact with an infected child.
Complications are rare but can include deeper tissue infections, rheumatic fever, and kidney disease.
Who’s At Risk
- Scarlet fever is rare in children under the age of 2, because substances from the mother's immune system (antibodies) protect the child up to that age.
- The peak ages for infection are 4-8 years. By age 10, most children have developed their own immunity to the toxin.
- Because infection is spread by fluids from the airways (respiratory secretions), infection rates are higher in crowded situations.
Signs & SymptomsScarlet fever is accompanied by a sandpaper-like rash of 1-2 mm red bumps, which merge together, starting on the neck, then moving to the trunk, and finally to the arms and legs (extremities). It is sometimes a bit itchy. If scarlet fever develops on body creases (armpits, elbow folds), red streaks may appear.
Fever, chills, body aches, nausea, vomiting, and loss of appetite may occur.
When the throat is the main area of infection, the tonsils may become enlarged, red, and tender. Other areas (lymph nodes) in the neck may become swollen. At first, the tongue has a white coating, giving a "white strawberry" tongue appearance, which then falls off (sheds) to reveal a bright red strawberry tongue. The rash does not affect the palms and soles at first, but later on, these areas may peel. The rash usually lasts for 4-5 days, and as it fades (subsides), skin on the neck and face start to peel, and eventually the hands and feet start to peel as well.
Self-Care GuidelinesIt is difficult to avoid infection of others who are not immune in the household. However, you might try to:
- Keep eating and clothing items used by an ill child away from other people, and wash them in hot soapy water.
- The child's caregivers should wash their hands frequently.
- Keep the child comfortable with acetaminophen (Tylenol) or ibuprofen for fever relief.
- Have your child eat soft foods, drink plenty of liquids, and apply lotions such as calamine for itching, if needed.
When to Seek Medical CareCall your child's doctor if you suspect that the child may have scarlet fever.
TreatmentsThe doctor will usually do a throat or skin culture or a rapid-strep test to confirm the diagnosis. If Streptococcus infection is confirmed, prescription antibiotics are will be prescribed, to be taken for about 10 days.
Bolognia, Jean L., ed. Dermatology, pp.1119-1120. New York: Mosby, 2003.
Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed. pp.1871-1873. New York: McGraw-Hill, 2003.
Scarlet fever in Adult