Parvovirus B19 may present with a transient generalized rash, small polyarticular joint swelling, and symmetrical pain. Which diagnosis fits this presentation?

• A. Osteomyelitis
• B. Parvovirus B19
• C. Lyme disease
• D. HIV

Answer: (B)

Parvovirus B19 infection in adults often causes an acute, symmetric arthritis of the small joints (especially hands and wrists) along with a transient generalized rash. This combination—joint swelling that is small-joint and symmetric plus a brief, widespread rash—is a classic presentation of parvovirus B19–related arthritis, which can mimic autoimmune arthritis but typically resolves over weeks and is self-limited.

This fits best because osteomyelitis would show focal bone infection with localized bone pain and tenderness, not a generalized rash and symmetric small-joint swelling. Lyme disease can cause arthritis, but the typical pattern is migratory or oligoarticular involvement with a history of tick exposure and a hallmark erythema migrans rash at the site of a bite, not a generalized rash. HIV can have arthralgias and rashes, but the described pattern of a transient generalized rash with small-joint symmetry is most characteristic of parvovirus B19 infection.