A 9-year-old girl with an unremarkable medical history presented to the emergency department with a 6-day
history of left shoulder pain and a 2-day history of fever after having been hit by a tree limb blew out the top of
the tree. At present, she was febrile with a temperature of 39.4°C, appeared sick, and had a large area of erythema
over the left shoulder, with limited range of motion. Skin trauma was noted.
Physical examination: Showed slight swelling on the shoulder and small superficial wound, slight redness and
increased temperature in surrounding area with effusion in the joint. The left shoulder revealed movements of
the joint was reduced and associated with severe pain. Neurological and vascular examination of the limb was
satisfactory.
X-rays of the left shoulder : showed beginning ostoearthritic changes.
Laboratory results:
Needle puncture of erythema area obtained yellowish pus. Gram stain of the pus was as showed.
Question 1. Report microscopic examination