There have been concerns raised about insufficient length of needles on epinephrine autoinjectors as well as fear of interosseous injection due to excess length (Dreborg). There is a publication stating that 43% of children from 7.5-15 kg, the indication for the new dose formulation, could experience interosseous injection or bone contact with the needle using the standard 14.7 mm needle (Kim). This risk prompted the reduction in size of the needle on the 0.1mg device. I cannot comment on this being a "necessary modification", but it seems reasonable. The gauge is and the length is.
1. Dreborg, Sten, et al. "Do epinephrine auto-injectors have an unsuitable needle length in children and adolescents at risk for anaphylaxis from food allergy?." Allergy, Asthma & Clinical Immunology 12.1 (2016): 11.
2. Kim, Laura, et al. "Children under 15 kg with food allergy may be at risk of having epinephrine auto-injectors administered into bone." Allergy, Asthma & Clinical Immunology 10.1 (2014): 40.
I hope this information is of help to you in your practice.
All my best.
Dennis K. Ledford, MD, FAAAAI