Internal Medicine

0521779407-17 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:18

Parvovirus B19 1141

■Prior onset EI nonspecific symptoms fever, malaise, myalgias, head-

ache that lasts 2–3 days, followed 7–10 days later with characteristic

exanthem

■Exanthem: 3 stages;

➣facial rash; fiery red rash and cheeks (slapped cheek)

➣symmetric maculopapular rash on arms, move caudally to trunk,

buttocks, thighs

➣central clearing of rash leads to a lacy or reticular pattern

➣rash can recur, fluctuating in intensity, weeks or months

➣rash is often pruritic, and take any form such as morbilliform,

hemorrhagic/urticarial/vesicular/erythema-multiforme like

■arthralgia/arthritis – peripheral joints, symmetric, common in

adults, especially adult female patient

■Sometimes asymptomatic

➣Sometimes mild respiratory illness without rash

tests

Nonspecific

■WBC is usually normal/mild eosinophilia occasionally noted

Specific

■Serum B19- IgM antibody best test for acute infection in normal

hosts-single serum usually sufficient to establish diagnosis, IgM is

almost always present at time of rash, these tests may not be widely

available

■B19-IgG antibody-useful for demonstrating past infection and

immunity

■IgM and IgG antibody tests are immunoblot assays or EIA

■PCR tests on clinical specimens available in some settings and may

be particularly useful in immunocompromised host

■Antigen detection methods available in some settings, especially for

tissue specimens

■Electron microscopy can be used for tissues

differential diagnosis

■Rubella – rash may be similar, serology can distinguish

■Scarlet fever – lack of pharyngitis in EI, positive Strep culture in Scar-

let fever

■Collagen vascular disease

■Drug reactions