Septic Arthritis of the Shoulder following Recent Varicella Zoster Virus Infection in an 18-month-old Child: A Case Report.

We present a case of an 18-month-old female child who attended the paediatric emergency department with mild dehydration, pyrexia and a healing chickenpox (varicella) rash. Her older brother recently recovered from chickenpox without complication and is believed to have been the source of her infection. Her classically self-limiting condition was initially treated supportively with oral fluids and benzydamine mouth spray, before two further presentations to the emergency department with worsening clinical deterioration, a protracted pyrexia and an exquisitely painful right shoulder prompted the search for an alternative diagnosis. This ordinarily fit and well, immunocompetent girl was subsequently diagnosed with septic arthritis of the right shoulder, complicated by concurrent varicella zoster virus infection. She was managed operatively with needle arthrocentesis, using a two-cannula technique to thoroughly wash out the infected glenohumeral joint. An intra-operative pus sample was sent for culture, subsequently growing Group A streptococcus pyogenes. Following washout, she received a course of intravenous antibiotics. There was immediate clinical recovery in the function of the right shoulder joint which continued into the post-operative period. Down-trending infection markers demonstrated a biochemical improvement, and she was discharged from hospital with a three-week course of oral antibiotics, making a full recovery. The rarity of upper limb involvement, along with the operative management technique of two needle arthrocentesis joint washout make this case an important contribution to the existing knowledge base and highlights the importance of considering this surgical emergency presenting in - what is usually - an overwhelmingly benign and self-limiting illness.