Dengue Fever

J Am Acad Dermatol. 2008 Feb;58(2):308-16. Abstract quote

BACKGROUND: Dengue fever is the most common identifiable cause of acute febrile illness among travelers returning from South America, South Central Asia, Southeast Asia, and the Caribbean. Although the characteristic exanthem of dengue fever occurs in up to 50% of patients, few descriptions of it are found in the dermatology literature, and discussions of how to distinguish the dengue exanthem from other infectious disease entities are rare. Chikungunya fever is an emerging infectious disease now seen in returning US tourists and should be considered in the differential diagnosis of dengue fever in the appropriate patient.

OBJECTIVE: The purpose of our study was to report two cases of dengue fever among returning US tourists, provide a review of dengue fever, offer an extensive differential diagnosis of dengue fever, and raise awareness among dermatologists of chikungunya fever.

METHODS: This study includes clinical findings of two returning travelers, one who traveled to Mexico and the other to Thailand, complemented by a discussion of both dengue fever and its differential diagnosis.

LIMITATIONS: Limited to 2 case reports.

CONCLUSION: Dengue fever should be considered in the differential diagnosis of fever and rash in the returning traveler. Dermatologists should be aware of the distinctive exanthem of dengue fever. Recognition of the dengue fever rash permits a rapid and early diagnosis, which is critical, as dengue fever can progress to life-threatening dengue hemorrhagic fever or dengue shock syndrome.

Epidemiology
Disease Associations
Pathogenesis
Laboratory/Radiologic/Other Diagnostic Testing
Gross Appearance and Clinical Variants
Histopathological Features and Variants
Special Stains/ Immunohistochemistry/ Electron Microscopy
Differential Diagnosis
Prognosis
Treatment
Commonly Used Terms
Internet Links

EPIDEMIOLOGY	CHARACTERISTICS
SYNONYMS	Breakbone fever
INCIDENCE	One of the most important mosquito-borne viral diseases Over 10 million cases/year
GEOGRAPHY	See map below
Dengue hemorrhagic fever in a British travel guide Sonja Radakovic-Fijan, MD Wolfgang Graninger, MD Christian Müller, MD Herbert Hönigsmann, MD Adrian Tanew, MD Vienna, Austria	J Am Acad Dermatol 2002;46:430-3 Abstract quote A 44-year-old female British travel guide suddenly had fever, nausea, vomiting, and diarrhea develop during her stay in South India. Four days later she was transported to our hospital. At admission she had a high temperature, impaired respiration, and abdominal pain. Clinical examination revealed bilateral pleural effusion, hepatomegaly, and ascites. Two days later the patient showed a generalized macular rash with a conspicuous sparing of small islands of normal skin. Hemorrhagic erythema on the palms and soles as well as focal petechiae on the hard palate and scleral and conjunctival bleeding were also observed. Hypotension and renal insufficiency developed 1 week after the illness started. Laboratory investigations revealed highly elevated levels of hepatic enzymes, severe hemolytic anemia, decreased platelet counts, and abnormal coagulation values. The presumptive clinical diagnosis of dengue hemorrhagic fever was supported by serologic testing that disclosed sustained high titers of hemagglutination inhibition antibodies. Symptomatic therapy with substitution of volume and albumin, blood transfusions, and administration of antipyretics resulted in complete recovery within 6 weeks.

DISEASE ASSOCIATIONS	CHARACTERIZATION
Serotypes	No cross-protective immunity with each serotype-in theory, a person living in an endemic region may have four infections during their lifetimes
Case Fatality rate	5% Most fatal cases occur in children and young adults

LABORATORY/ RADIOLOGIC/ OTHER TESTS	CHARACTERIZATION
Viral serology markers	Only way to confirm the diagnosis by laboratory testing

GROSS APPEARANCE/ CLINICAL VARIANTS	CHARACTERIZATION
VARIANTS
Dengue fever
Dengue hemorrhagic fever	Extensive hemorrhage and easy bruising May lead to dengue shock syndrome
SKIN
The exanthem of dengue fever: Clinical features of two US tourists traveling abroad. Pincus LB, Grossman ME, Fox LP. Department of Dermatology at University of California, San Francisco, California, USA.	J Am Acad Dermatol. 2008 Feb;58(2):308-16. Abstract quote BACKGROUND: Dengue fever is the most common identifiable cause of acute febrile illness among travelers returning from South America, South Central Asia, Southeast Asia, and the Caribbean. Although the characteristic exanthem of dengue fever occurs in up to 50% of patients, few descriptions of it are found in the dermatology literature, and discussions of how to distinguish the dengue exanthem from other infectious disease entities are rare. Chikungunya fever is an emerging infectious disease now seen in returning US tourists and should be considered in the differential diagnosis of dengue fever in the appropriate patient. OBJECTIVE: The purpose of our study was to report two cases of dengue fever among returning US tourists, provide a review of dengue fever, offer an extensive differential diagnosis of dengue fever, and raise awareness among dermatologists of chikungunya fever. METHODS: This study includes clinical findings of two returning travelers, one who traveled to Mexico and the other to Thailand, complemented by a discussion of both dengue fever and its differential diagnosis. LIMITATIONS: Limited to 2 case reports. CONCLUSION: Dengue fever should be considered in the differential diagnosis of fever and rash in the returning traveler. Dermatologists should be aware of the distinctive exanthem of dengue fever. Recognition of the dengue fever rash permits a rapid and early diagnosis, which is critical, as dengue fever can progress to life-threatening dengue hemorrhagic fever or dengue shock syndrome.

HISTOPATHOLOGY	CHARACTERIZATION
VARIANTS
PLASMACYTOSIS
Dengue fever mimicking plasma cell leukemia. Gawoski JM, Ooi WW. Department of Laboratory Medicine, Lahey Clinic, Burlington, Mass 01805, USA.	Arch Pathol Lab Med. 2003 Aug;127(8):1026-7. Abstract quote Extreme plasmacytosis in peripheral blood is a rare finding most often associated with plasma cell leukemia but rarely with other malignancies, infectious diseases, or drug reactions. We report the case of a 40-year-old man who was a US expatriate working and traveling in East Asia. He presented with complaints of fever, myalgia, headache, vomiting, and diarrhea of 3 days' duration. An initial evaluation revealed elevated liver function tests, thrombocytopenia (68 x 10(3)/microL), and a white blood cell count of 5.8 x 10(3)/microL with 19% plasma cells (1100/microL), 9% abnormal plasmacytoid lymphocytes (520/microL), 37% polymorphonuclear leukocytes, 3% band forms, 27% lymphocytes, 4% monocytes, and 1% eosinophils. An extensive evaluation was performed, including infectious disease serologies, a bone marrow biopsy, and flow cytometry. During the course of 3 days, his symptoms and hematologic findings improved dramatically. Serologic results were reactive for dengue (immunoglobulin M [IgM] positive, reciprocal IgG titer, 655 360), consistent with a secondary infection of unknown serotype. He remains well 4 years later. To our knowledge, plasmacytosis to this degree has not been described in dengue fever, but atypical lymphocytosis is common. In patients from dengue-endemic areas, even extreme plasmacytosis should be assessed to determine whether it is transient and related to an acute illness before proceeding to an extensive evaluation.

PROGNOSIS AND TREATMENT	CHARACTERIZATION
PROGNOSIS
Survival	Dengue hemorrhagic fever is fatal in about 5 percent of cases, mostly among children and young adults
TREATMENT	Supportive
Vaccine	Attenuated candidate vaccine viruses have been developed in Thailand Effective dengue vaccine for public use will not be available for 5 to 10 years
	Developing second-generation recombinant vaccine viruses using the Thailand attenuated viruses as a template