Pediatric Problem Solving -Case 4

Problem Solving – Case 4
A mother brings to the clinic her 4 years old son who began complaining of Rt knee pain 2 weeks ago, is limping slightly, is fatigued and has had a fever 38.2C .
What is the important diagnostic Lab test to perform
A. CBC with differential

B. Sedimentation rate

C. EBV titre

D. Rheumatoid factor

Explanation of the case
a- Patient suffers from arthritis and not Arthralgia

b- Difference between them: Arthralgia is subjective pain (patient says he is in pain).But arthritis is detected by swelling / limitation of movement as in limping
c- Rt (unilateral) knee pain = not rheumatic fever i.e. not polyarthritis
d- 2 weeks = not trauma
 Choice A:the right answer
a) Points with: important to be done in the beginning to exclude major problems like Leukemia and to give hints on other diseases as viral infection, rheumatoid, acute infection.
b) Leukemia in CBC: lymphocytic count increased, anaemia and thrombocytopenia.
Choice B: a) Points against: not very useful as it is non-specific
Choice C: a) Points against: better do CBC first for the previous causes above
 Choice D: a) Points against: same as C + rheumatoid is mainly in small joints