Scarlet Fever Workup

Author: Edward J Zabawski Jr, DO; Chief Editor: Dirk M Elston, MD more...

Updated: Oct 13, 2011

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Histologic Findings
Approach Considerations
Blood and Urine Studies
Throat Culture
Antideoxyribonuclease B and Antistreptolysin O Titers
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Histologic Findings

The microscopic findings of the eruption of scarlet fever are nonspecific and have an appearance similar to that of other exanthematous eruptions. A sparse perivascular infiltrate is present, usually consisting primarily of lymphocytes with a slight amount of spongiosis in the epidermis. Slight parakeratosis may be present, which probably correlates with the sandpaperlike texture of the skin.

Approach Considerations

In addition to standard blood and urine tests done as part of a complete medical workup, the following studies are indicated in scarlet fever:

Throat culture or rapid streptococcal test
Anti-deoxyribonuclease B and antistreptolysin-O titers (antibodies to streptococcal extracellular products)

In most cases, no imaging studies are indicated.

Blood and Urine Studies

The complete blood count (CBC) commonly reveals a leukocytosis. The white blood cell (WBC) count in scarlet fever may increase to 12,000-16,000/μL, with a differential of up to 95% polymorphonuclear lymphocytes. During the second week, eosinophilia, as high as 20%, can develop.

Urinalysis and liver function tests may reveal changes associated with complications of scarlet fever. Said tests are part of a complete medical workup.

Patients whose bacterial source may suggest another process (eg, a patient with a suppurative leg wound who may have osteomyelitis) should be evaluated accordingly.

Throat Culture

Throat culture remains the criterion standard for confirmation of group A streptococcal upper respiratory infection. American Heart Association guidelines for prevention and treatment of rheumatic fever state that group A streptococci virtually always are found on throat culture during acute infection.^[14]

Throat cultures are approximately 90% sensitive for the presence of group A beta-hemolytic streptococci (GABHS) in the pharynx. However, because a 10-15% carriage rate exists among healthy individuals, the presence of GABHS is not proof of disease.

To maximize sensitivity, proper obtaining of specimens is crucial. Vigorously swab the posterior pharynx, tonsils, and any exudate with a cotton or Dacron swab under strong illumination, avoiding the lips, tongue, and buccal mucosa.

Direct antigen detection kits (ie, rapid antigen tests [RATs], strep screens) have been proposed to allow immediate diagnosis and prompt administration of antibiotics. Kits are latex agglutination or a costlier enzyme-linked immunosorbent assay (ELISA). Several studies of RAT kits report results of 95% specificity but only 70-90% sensitivity. Operator technique can also significantly influence the results of the test.^[15]

Antideoxyribonuclease B and Antistreptolysin O Titers

Streptococcal antibody tests (eg, antideoxyribonuclease B [ADB] and antistreptolysin O [ASO] titers) are used to confirm previous group A streptococcal infection. The most commonly available streptococcal antibody test is the ASO test. An increase in ASO titers can sometimes be observed but is a late finding and usually of value only in retrospect.

Streptococcal antibody tests can provide confirmatory evidence of recent infection but have no value in acute infection and currently are not indicated in this setting. They may be of value in patients with suspected acute renal failure or acute glomerulonephritis.

Proceed to Treatment & Management

Contributor Information and Disclosures

Author

Edward J Zabawski Jr, DO Medical and Surgical Dermatology

Disclosure: Nothing to disclose.

Coauthor(s)

Garry Wilkes MBBS, FACEM, Director of Emergency Medicine, Calvary Hospital, Canberra, ACT; Adjunct Associate Professor, Edith Cowan University; Clinical Associate Professor, Rural Clinical School, University of Western Australia

Disclosure: Nothing to disclose.

Grace M Young, MD Associate Professor, Department of Pediatrics, University of Maryland Medical Center

Grace M Young, MD is a member of the following medical societies: American Academy of Pediatrics and American College of Emergency Physicians

Disclosure: Nothing to disclose.

Jerry Balentine, DO Professor of Emergency Medicine, New York College of Osteopathic Medicine; Executive Vice President, Chief Medical Officer, Attending Physician in Department of Emergency Medicine, St Barnabas Hospital

Jerry Balentine, DO is a member of the following medical societies: American College of Emergency Physicians, American College of Osteopathic Emergency Physicians, American College of Physician Executives, American Osteopathic Association, and New York Academy of Medicine

Disclosure: Nothing to disclose.

Pamela L Dyne, MD Professor of Clinical Medicine/Emergency Medicine, University of California, Los Angeles, David Geffen School of Medicine; Attending Physician, Department of Emergency Medicine, Olive View-UCLA Medical Center

Pamela L Dyne, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Peter Bloomfield, MD, MPH Clinical Instructor, Department of Emergency Medicine, Olive View-UCLA Medical Center

Disclosure: Nothing to disclose.

Joseph A Salomone III, MD Associate Professor and Attending Staff, Truman Medical Centers, University of Missouri-Kansas City School of Medicine; EMS Medical Director, Kansas City, Missouri

Joseph A Salomone III, MD is a member of the following medical societies: American Academy of Emergency Medicine, National Association of EMS Physicians, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Daniel P Lombardi, DO Clinical Assistant Professor, New York College of Osteopathic Medicine; Clinical Instructor, Albert Einstein College of Medicine of Yeshiva University; Attending Physician and Program Director, Department of Emergency Medicine, St Barnabas Hospital

Daniel P Lombardi, DO is a member of the following medical societies: American College of Emergency Physicians, American College of Osteopathic Emergency Physicians, and American Osteopathic Association

Disclosure: Nothing to disclose.

Specialty Editor Board

Craig A Elmets, MD Professor and Chair, Department of Dermatology, Director, UAB Skin Diseases Research Center, University of Alabama at Birmingham School of Medicine

Craig A Elmets, MD is a member of the following medical societies: American Academy of Dermatology, American Association of Immunologists, American College of Physicians, American Federation for Medical Research, and Society for Investigative Dermatology

Disclosure: Palomar Medical Technologies Stock None; Astellas Consulting fee Review panel membership; Massachusetts Medical Society Salary Employment; Abbott Laboratories Grant/research funds Independent contractor; UpToDate Salary Employment; Biogen Grant/research funds Independent contractor; Clinuvel Independent contractor; Covan Basilea Pharmaceutical Grant/research funds Independent contractor; ISDIN None Consulting; TenX BIopharma Grant/research funds Independent contractor

Richard P Vinson, MD Assistant Clinical Professor, Department of Dermatology, Texas Tech University Health Sciences Center, Paul L Foster School of Medicine; Consulting Staff, Mountain View Dermatology, PA

Richard P Vinson, MD is a member of the following medical societies: American Academy of Dermatology, Association of Military Dermatologists, Texas Dermatological Society, and Texas Medical Association

Disclosure: Nothing to disclose.

Eric L Weiss, MD, DTM&H Medical Director, Office of Service Continuity and Disaster Planning, Fellowship Director, Stanford University Medical Center Disaster Medicine Fellowship, Chairman, SUMC and LPCH Bioterrorism and Emergency Preparedness Task Force, Clinical Associate Progressor, Department of Surgery (Emergency Medicine), Stanford University Medical Center

Eric L Weiss, MD, DTM&H is a member of the following medical societies: American College of Emergency Physicians, American College of Occupational and Environmental Medicine, American Medical Association, American Society of Tropical Medicine and Hygiene, Physicians for Social Responsibility, Southeastern Surgical Congress, Southern Association for Oncology, Southern Clinical Neurological Society, and Wilderness Medical Society

Disclosure: Nothing to disclose.

Robert E O'Connor, MD, MPH Professor and Chair, Department of Emergency Medicine, University of Virginia Health System

Robert E O'Connor, MD, MPH is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American College of Physician Executives, American Heart Association, American Medical Association, Medical Society of Delaware, National Association of EMS Physicians, Society for Academic Emergency Medicine, and Wilderness Medical Society

Disclosure: Nothing to disclose.

Chief Editor

Dirk M Elston, MD Director, Ackerman Academy of Dermatopathology, New York

Dirk M Elston, MD is a member of the following medical societies: American Academy of Dermatology

Disclosure: Nothing to disclose.

References

Dong H, Xu G, Li S, Song Q, Liu S, Lin H, et al. Beta-haemolytic group A streptococci emm75 carrying altered pyrogenic exotoxin A linked to scarlet fever in adults. J Infect. Apr 2008;56(4):261-7. [Medline].
Yang SG, Dong HJ, Li FR, Xie SY, Cao HC, Xia SC, et al. Report and analysis of a scarlet fever outbreak among adults through food-borne transmission in China. J Infect. Nov 2007;55(5):419-24. [Medline].
Cunningham MW. Pathogenesis of group A streptococcal infections. Clin Microbiol Rev. Jul 2000;13(3):470-511. [Medline]. [Full Text].
Leslie DL, Kozma L, Martin A, Landeros A, Katsovich L, King RA, et al. Neuropsychiatric disorders associated with streptococcal infection: a case-control study among privately insured children. J Am Acad Child Adolesc Psychiatry. Oct 2008;47(10):1166-72. [Medline]. [Full Text].
Sandrini J, Beucher AB, Kouatchet A, Lavigne C. [Scarlet fever with multisystem organ failure and hypertrophic gastritis]. Rev Med Interne. May 2009;30(5):456-9. [Medline].
Gómez-Carrasco JA, Lassaletta A, Ruano D. [Acute hepatitis may form part of scarlet fever]. An Pediatr (Barc). Apr 2004;60(4):382-3. [Medline].
Güven A. Hepatitis and hematuria in scarlet fever. Indian J Pediatr. Nov 2002;69(11):985-6. [Medline].
Lau SK, Woo PC, Yuen KY. Toxic scarlet fever complicating cellulitis: early clinical diagnosis is crucial to prevent a fatal outcome. New Microbiol. Apr 2004;27(2):203-6. [Medline].
Finnish Medical Society Duodecim. Sore throat and tonsillitis. EBM Guidelines. Evidence-Based Medicine. Feb 2 2007Helsinki, Finland: Wiley Interscience. John Wiley & Sons;[Full Text].
Gidaris D, Zafeiriou D, Mavridis P, Gombakis N. Scarlet Fever and hepatitis: a case report. Hippokratia. Jul 2008;12(3):186-7. [Medline]. [Full Text].
Reddy UP, Albini TA, Banta JT, Davis JL. Post-streptococcal vasculitis. Ocul Immunol Inflamm. Jan-Feb 2008;16(1):35-6. [Medline].
Gaston DA, Zurowski SM. Arcanobacterium haemolyticum pharyngitis and exanthem. Three case reports and literature review. Arch Dermatol. Jan 1996;132(1):61-4. [Medline].
Sanz JC, Bascones Mde L, Martín F, Sáez-Nieto JA. [Recurrent scarlet fever due to recent reinfection caused by strains unrelated to Streptococcus pyogenes]. Enferm Infecc Microbiol Clin. Jun-Jul 2005;23(6):388-9. [Medline].
Gerber MA, Baltimore RS, Eaton CB, Gewitz M, Rowley AH, Shulman ST, et al. Prevention of rheumatic fever and diagnosis and treatment of acute Streptococcal pharyngitis: a scientific statement from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young, the Interdisciplinary Council on Functional Genomics and Translational Biology, and the Interdisciplinary Council on Quality of Care and Outcomes Research: endorsed by the American Academy of Pediatrics. Circulation. Mar 24 2009;119(11):1541-51. [Medline].
Gerber MA, Shulman ST. Rapid diagnosis of pharyngitis caused by group A streptococci. Clin Microbiol Rev. Jul 2004;17(3):571-80, table of contents. [Medline]. [Full Text].
Bass JW. Antibiotic management of group A streptococcal pharyngotonsillitis. Pediatr Infect Dis J. Oct 1991;10(10 Suppl):S43-9. [Medline].
Derrick CW, Dillon HC. Erythromycin therapy for streptococcal pharyngitis. Am J Dis Child. Feb 1976;130(2):175-8. [Medline].
Stock I. [Streptococcus pyogenes--much more than the aetiological agent of scarlet fever]. Med Monatsschr Pharm. Nov 2009;32(11):408-16; quiz 417-8. [Medline].

The exudative pharyngitis typical of scarlet fever. Although the tongue is somewhat out of focus, the whitish coating observed early in scarlet fever is visible.

Desquamation of the palms is a frequently observed self-limited manifestation of scarlet fever present in the healing period following resolution of the infection and acute eruption.

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