Subcutaneous immunotherapy (SIT) injections for aeroallergens are often utilized in patients. SIT should be injected into the subcutaneous space in the mid-posterolateral upper arm. If the injections are given intramuscularly (IM), there may be an increased risk of anaphylaxis. In our allergy clinic, SIT is given with BD Safety Glide™ Allergy syringes with needle length 13 mm. There is a risk of the SIT being injected IM if patients have a skin to muscle depth (STMD) less than 13 mm.