Since early in life, she was prescribed a pediatric EAI (EpiPen Jr ; 0.15 mg) in case of an allergic emergency. The first use of her prescribed EAI for MS was at age 6, and she has had 2 subsequent allergic emergencies requiring the use of her EAI as of the date of this report (Table 2). At 6 years old, her height was 117 cm, weight was 17.7 kg, BMI was 12.9, and her STBD was 10.7 mm by ultrasound of the right mid-anterolateral thigh. At 7 years old, around her second event requiring the EpiPen Jr , her height was 122 cm, weight was 25 kg, and her STBD was not recorded. After this event, and during her observation period in the hospital, MS complained of pain immediately in her right thigh at the injection site. X-ray and ultrasound results were negative. It is believed that MS suffered an unintentional bone injection with her EAI based on clinical presentation following the allergic emergency. At 9 years old, her height was 141 cm, weight was 30 kg, and her STBD was 12.1 mm. In 2017, MS was evaluated again for pain and discomfort in her right thigh. 
The indication for the EpiPen Jr  is for children between 15 and 30 kg and this device has a needle length of 12.7 mm. MS and her parents were made aware that use of her prescribed EAI could cause an unintentional injection to the bone using the standard injection technique with compression. It was suggested that, prior to injection, the vastus lateralis muscle be squeezed as to avoid full compression while using her EAI because of the high risk of unintentional bone injection.
This case of possible bone injection was reported to Health Canada.