Features of the joint involvement:
(1) It is usually symmetrical.
(2) An affected joint may be painful, swollen and stiff.
(3) It tends to affect the small joints of the hands and feet.
(4) It usually lasts 1 to 3 weeks but may last for months or years.
Clinical features that may suggest the diagnosis:
(1) transient skin rash prior to or concurrent with onset of joint involvement
(2) unexplained anemia
(3) close contact with small children
(4) outbreak of fifth disease (erythema infectiosum) or contact with someone with it
Reasons for misdiagnosis:
(1) none of the clinical features are identified
(2) rheumatoid factor is detected (may be produced transiently in a patient with parvovirus 19 infection)
(3) chronic arthropathy that meets criteria for rheumatoid arthritis or other arthropathy
Testing for parvovirus B19 antibodies can be done for a patient with acute onset of arthropathy, but diagnosis of chronic arthritis is problematic.
