Scarlet fever is a disease caused by an exotoxin released by Streptococcus pyogenes Group A and occurs rarely with impetigo or other streptococcal infections. It is characterized by sore throat, fever, a 'strawberry' tongue, and a fine sandpaper rash over the upper body that may spread to cover almost the entire body. Scarlet fever is notrheumatic fever, but may progress into that condition. The rate of development of rheumatic fever in individuals with untreated streptococcal infection is estimated to be 3%. The rate of development is far lower in individuals who have received antibiotic treatment.
Streptococcus pyogenes (group A streptococcus) is responsible for scarlet fever. It can also cause simple angina, erysipelas and serious toxin-mediated syndromes like necrotizing fasciitis and the so-called streptococcal toxic shock-like syndrome. The virulence of group A streptococcus seems to be increasing lately. The exanthem of scarlatina is thought to be due to erythrogenic toxin production by specific streptococcal strains in a nonimmune patient. Along with erythrogenic toxins, the Group A streptococcus produces several toxins and enzymes. Two of the most important are the streptolysins O and S. Streptolysin O, an hemolytic, thermolabile and immunogenic toxin, is the base of an assay for scarlatina and erysipelas - the anti-streptolysin O titer.
This disease was also once known as Scarlatina (from the Italian scarlattina). Many novels depicting life before the nineteenth century (see Scarlet fever in popular culture below) describe scarlet fever as an acute disease being followed by many months spent in convalescence. The convalescence was probably due to complications with rheumatic fever. Prior to an understanding of how streptococcus was spread, it was also not uncommon to destroy or burn the personal effects of a person afflicted with scarlet fever to prevent transmission to other people.
Signs and symptoms
Early symptoms indicating the onset of scarlet fever can include:
Punctate red macules on the hard and soft palate and uvula (ie, Forchheimer spots).
Bright red tongue with a "strawberry" appearance
Characteristic rash, which:
is fine, red, and rough-textured; it blanches upon pressure
appears 12–48 hours after the fever
generally starts on the chest, axilla (armpits), and behind the ears
is worse in the skin folds
Pastia lines (where the rash becomes confluent in the arm pits and groins) appear and persist after the rash is gone
The rash begins to fade three to four days after onset and desquamation (peeling) begins. "This phase begins with flakes peeling from the face. Peeling from the palms and around the fingers occurs about a week later and can last up to a month." Peeling also occurs in axilla, groin, and tips of the fingers and toes.
Diagnosis of scarlet fever is clinical. The blood tests shows marked leukocytosis with neutrophilia and conservated or increased eosinophils, high ESR and CRP , and elevation of antistreptolysin O titer. Blood culture is rarely positive, but the streptococci can usually be demonstrated in throat culture. The complications of scarlet fever include septic complications due to spread of streptococcus in blood and immune-mediated complications due to an aberrant immune response. Septic complications, today rare, include otitis, sinusitis, streptococcal pneumonia, empyema thoracis, meningitis and full-blown septicaemia ( malignant scarlet fever).
Immune complications include acute glomerulonephritis, rheumatic fever and erythema nodosum. The secondary scarlatinous disease (or secondary malignant syndrome of scarlet fever) included renewed fever, renewed angina, septic ORL complications and nephritis or rheumatic fever and is seen around the 18th day of untreated scarlet fever.
Other than the occurrence of the diarrhea, the treatment and course of scarlet fever are no different from those of any strep throat. In case of penicillin allergy, clindamycin or erythromycin can be used with success.
The Velveteen Rabbit by Margery Williams (1922) - The main protagonist, a small boy, contracts scarlet fever and his toys are all burned. Indeed, the velveteen rabbit itself, the boy's favorite toy, was going to be burned by a nurse, but at the book's climax, the toy rabbit comes alive and joins the "real" rabbits outside in the garden.
By the Shores of Silver Lake by Laura Ingalls Wilder (1939) - Before the start of the book, Laura's older sister Mary has been left blind by a bout with scarlet fever.
Frankenstein; or, The Modern Prometheus by Mary Wollstonecraft Shelley (1818) - Victor Frankenstein's adoptive sister Elizabeth contracts scarlet fever and recovers. But Victor's mother, who contracts the scarlet fever from Elizabeth, dies.
The Witch of Blackbird Pond (1958) by Elizabeth George Spears - A young girl from Barbados is accused of giving scarlet fever to her cousins by using witchcraft.
Fever Dream by Ray Bradbury - the young protagonist is diagnosed with scarlet fever, though it appears to mutate into something much more sinister.
Private Peaceful by Michael Morpurgo - Molly gets scarlet fever and survives.
The first episode of the television show Ozzy & Drix featured a villain named Scarlet Fever, who died after getting sucked into the spleen and shredded.
In the 2001 film Osmosis Jones, the main antagonist is a strain of scarlet fever known as "Thrax," whose goal is to "get his own chapter in the medical book" after taking out his host, Frank, in 48 hours. He had the ability to light fire to anything he touched, but was killed when he fell into a jar of rubbing alcohol. Thrax is voiced by Laurence Fishburne.
An American soldier in The Steel Helmet lost all of his hair as a child due to Scarlet Fever.
Anna Jones, mother of the young Henry 'Indiana' Jones died of Scarlet Fever during the year of 1912
^ ab Balentine J and Kessler D (March 7, 2006). "Scarlet Fever". eMedicine. emerg/518.
^ ab Dyne P and McCartan K (October 19, 2005). "Pediatrics, Scarlet Fever". eMedicine. emerg/402.