CHALL PED CASE Fever, Diarrhea, and Rash in a 9-Month-Old Boy AHEI LCV

A previously healthy 9-month-old boy is brought to the emergency department
having
3 days of fever and diarrhea and a rash that appeared today.
Physical examination reveals an alert infant whose vital signs are normal except for
a temperature of 101.6°F (38.7°C). A palpable purpuric rash is visible over his face,
ears, arms, and legs, but the trunk is spared. The remainder of the examination is
unremarkable. Urinalysis is negative for blood or protein. A complete evaluation for
sepsis, including lumbar puncture, yields normal findings. Intravenous antibiotics
are started.
Over the following days, the fever subsides and the rash starts to clear. Blood and
cerebrospinal culture results are sterile, antibiotics are stopped, and the infant
is discharged. Two days later he is readmitted because of a flare-up of the rash
and the development of tender edema of the right lower extremity with no signs
of arthritis. His temperature is 100.2°F (37.9°C), and he looks well. The results of
a technetium bone scan are normal. Serologic testing for seasonal viruses gives
negative
results. Levels of complement and immunoglobulins are normal. A skin
biopsy reveals the diagnosis.