Quiz 13 - 14 year old with bruising and shoulder pain

Below is an X-Ray of a 14 year old boy who presented with pain in his left shoulder for 1 month that has significantly incresed over last 24 hours. He has also noticed easy bruising for last 1 month. On Examination there is tenderness, crepitus and decreased mobility of the left shoulder. You also notice an erythematous papular rash in the axillary folds and over the nape. Otoscopy reveals bilateral draining ears.

What is the diagnosis ?