Botulinum toxin injection pain is less with smaller-gauge needles, says study
Injection of botulinum toxin type A through 32-gauge needles is slightly less painful than injection through 30-gauge needles, according to a randomised trial.
Dermatologists routinely use 30-gauge needles for facial injections of neurotoxins, prepackaged fillers, and intralesional local anaesthesia, but pain is still an issue even with these small-gauge needles.
Dr Murad Alam, from Feinberg School of Medicine, Northwestern University, Chicago, and colleagues compared discomfort associated with superficial cutaneous injections of botulinum toxin type A using 30- and 32-gauge needles in a split-face randomised trial of 20 patients. They also compared the discomfort of saline injections into the upper arms using the two needles.
Mean injection pain scores for the face were nominally lower with the 32-gauge needle (3.41/10) than with the 30-gauge needle (4.16/10). The mean pain scores were lower for the arm injections (1.21 with the 32-gauge needle and 1.66 with the 30-gauge needle).
Clinically significant pain was 3.8 times more likely with facial injections with 30-gauge needles than with 32-gauge needles (p=0.04), whereas there were no clinically significant differences in pain associated with needle type with arm injections, according to the JAMA Dermatology online report.
Pain descriptors (throbbing, shooting, stabbing, and so on) did not differ significantly between the needle types.
“This study is important because it suggests that for a subset of patients prone to experience clinically significant pain on injection with botulinum toxin type A to the face, such pain can be mitigated by selection of smaller-bore needles,” the researchers concluded.
“To minimise avoidable expense, routine use of costly 32-gauge needles could be restricted to the subset of patients who have in earlier treatments encountered clinically significant pain with larger-bore needles,” they added.
