Andrea Buitrago
Take Home 6
Dr. Gallo
November 1, 2013
Disease: Scarlet Fever
“Scarlatina”, was the name given to a disease that proved to be a major cause of death in the
19th and early 20th centuries. The common name of this infectious disease is called Scarlet Fever. It is
triggered by the onset of a throat infection, much like step throat. It was not until the introduction of
Penicillin, which was discovered in 1928 by Alexander Fleming, that the disease died down.
(http://en.wikipedia.org/wiki/Scarlet_fever#Presentation) This antibiotic is effective in treating
infections, usually within ten days, however there are no current vaccines.
Streptococcus pyogenes, gram positive and belonging to Group A beta-hemolytic strep,
produces erythrogenic toxin, when a bacteriophage infects this bacterium. The secretion of pyrogenic
exotoxins infects strep and thus causes the disease. Different strains of S. pyogenes can produced
different types of toxins and depending on the concentration, if small, the toxin cannot be detected.
However, strains produce this toxin aren’t necessarily more dangerous than others that don’t; strains
that produce erythrogenic toxins are easy to diagnose due to characteristic features. The T12
bacteriophage integrates in the strep genome and transcribes for the toxin, more specifically, “the
phage integrates into a serine tRNA gene on the chromosome” (Scarlet Fever). In 1986, the gene was
cloned and sequenced by Weeks and Ferretti, having 753 base pairs.(
http://en.wikipedia.org/wiki/Scarlet_fever#Presentation)
Strep throat is targets children from 5-15, but affects all susceptible.
(http://www.medicalnewstoday.com/articles/176242.php) Common features include: bright, red
tongue with whitish or yellowish coating, red cheeks, pale area around mouth, reddened sore throat,
fever at or about 101oF, swollen neck glands, a rough rash that starts from the chest, armpits and behind
ears (and possibly groin area) and may eventually spread to the uvula, Pastia lines in skin folds; after
about four days, skin peeling occurs starting from the face to the palms, fingers, toes, armpits and groin
a week later. The rash is the most recognizable symptom, since it looks like a sunburn along with small
bumps (that may itch). Also, the tonsils and back of throat can be covered with spotted speck of puss
and appear red or swollen. Chills, aches, nausea, vomiting and loss of appetite may also be accompanied
by these symptoms. Scarlet fever can arise from the streptococcal skin infection, impetigo, in rare cases.
After the onset of throat infection, fever arises and stops within 3-5 days. A sore throat and skin
peeling are then brought on by the 6th day, which is when the rash fades away. It usually takes a few
weeks for the tonsils and neck glands to return to normal.
(http://en.wikipedia.org/wiki/Scarlet_fever#Presentation)
Clinically, blood tests are used for diagnosis, showing leukocytosis with neutrophilia, C-reactive
proteins which indicate inflammation as well as high erythrocyte sedimentation rates, and the elevation
of antistreptolysin O titer. Interestingly, the Far East scarlet fever, first reported in Russia, is caused by
gram negative bacillus, Yersinia pseudotuberculosis. Kawasaki disease is also similar, but lacks some
symptoms and doesn’t show up initially but can spring up over a few days. Such cases need to be
differentiated in diagnosis. Antibiotics like penicillin, amoxicillin, azithromycin, clarithromycin,
clindamycin, and cephalosporins like cephalexin are used in treatment.
(http://en.wikipedia.org/wiki/Scarlet_fever#Presentation)
Strains of scarlet fever are sensitive to beta-lactam antibiotics like penicillin. Resistant strains, to
macrolide antibiotics (like erythromycin) have surfaced in 2011 in Hong Kong possibly due to the
overuse of macrolide antibiotics. In 1924, George and Gladys Dick invented a vaccine, however it was
discontinued due to poor efficacy. The wide variety of strains, and number of testing needed on human
trails make it difficult to produce a successful vaccine. The Dick Test, which is no longer used, was
invented to identify people susceptible to scarlet fever, consisted of taking a broth filtrate from an
erythrogenic toxin producing strain and injecting it intracutaneously. Erythematous and oedematous
skin reactions would occur after 24 hours, and the injection of antitioxin into the site neutralized the
reaction. If the person was not reactive, they had enough antibodies and were not susceptible.
(http://en.wikipedia.org/wiki/Scarlet_fever#Presentation)
Scarlet fever is highly contagious and can be spread through inhalation, skin contact or fomites.
A food outbreak from chicken has even been reported in China. PVL, Panton-Valentin leukocidin, is a
cytotoxin that targets human and rabbit neutrophils, and macrophages. Staphyloccocus aureus strains
can produce it as a virulence factor and is associated with Methicillin resistance. It manifests skin
infections and pneumonia. (http://en.wikipedia.org/wiki/Scarlet_fever#Presentation)
Common complications include: ear infections, pneumonia, throat abscesses, sinusitis,
inflammation of kidneys (glomerulonephritis), and rheumatic fever and skin infections. Kidney failure is
a frequent complication along with meningitis, Necrotizing fasciitis, endocarditis, osteomyelitis, toxic
shock syndrome, Pediatric autoimmune neuropsychiatric disorders associated with streptococcal
infections, OCD, Tourette syndrome and ADHD.
(http://www.medicalnewstoday.com/articles/176242.php)
For prevention, one should isolate the infected and hand-wash frequently. The infected person
should receive lots of liquids and kept in a cool environment. Lotions can be used to appease itchy skin
and pain killers for aches and alleviating fevers.
(http://www.medicalnewstoday.com/articles/176242.php)
References:
Medical News Today. MediLexicon International, n.d. Web. 01 Nov. 2013.
"Scarlet Fever." Wikipedia. Wikimedia Foundation, 30 Oct. 2013. Web. 01 Nov. 2013.