Aims To describe the demographics and clinical presentation of children who attended the emergency department of Temple Street hospital with acute onset difficulty in walking or refusal to walk and who were subsequently diagnosed with benign acute myositis.

Methods We collected a list of all the ED patients who had a raised Creatinine kinase result from the pathology laboratory. We used the Emergency Department Clinical Information System, Symphony to review the medical records of these children and collect the data we needed.

Results Fifty one (51) children, (40 males and 11 females) were seen with clinical myositis and raised Creatinine kinase levels between November and February of 2012–2013. Mean age was 5.9 years. Twenty eight (54.9%) presented with leg pain, sixteen (29.4%) non-weight bearing and seven (5.9%) with difficulty walking. 64.7% of these patients had calf tenderness, 5.9% had thigh tenderness and in 29.4% muscle tenderness was not clearly documented in the clinical notes. There was evidence of concurrent viral disease in thirty one (61%) of these patients with nineteen (37.2%) having had a viral illness in the preceding week. Creatinine Kinase levels were elevated in all patients with levels ranging from 183 – 7584.

Conclusion Benign acute childhood myositis (BACM) is a syndrome more commonly seen in childhood typically affecting males. Symptoms include calf pain and refusal or difficulty to walk, often after a viral illness. It has been epidemiologically linked to Influenza virus. Previous studies have described much fewer cases.

The Temple street University Hospital emergency department (ED) is one of the busiest in Western Europe and in the 2012/2013 winter months we did experience a surge of children with this history. BACM can be differentiated from other more serious causes of difficulty walking in children by the presence of calf tenderness in the presence of otherwise normal lower limb exam on a background of concurrent or preceding viral illness as shown in this study. These children may not necessarily need extensive investigation or routine follow up but can be discharged with appropriate advice to parents to seek review if symptoms continue.