Sign of the school knapsack: myositis of the trapezius muscles caused by overload.

A 12-year-old boy had bilateral ocular pain with eye reddening, papilledema, and vitreous inflammation. Sarcoidosisand tuberculosis were among the diseases suspected. Ga-67 citrate imaging showed bilateral uptake in both trapezius muscles. The patient carried a knapsack and the increased uptake appeared to be due to trapezius myositiscaused by overload.