Surface Analgesia - all you need is a toothbrush!
Relieving the pain of local anesthetic injections and other surface-based treatments has always been something we as podiatrists have tried to achieve to give of our patient’s maximum comfort. As a student I remember having to learn about techniques to reduce the pain of injections such as warming the anaesthetic prior to injecting, cooling the skin prior to treatment or the use of topical anaesthetic creams such as Emla.
In a recent edition of the journal “Paediatric Dermatology” a paper highlights a novel use for an electric toothbrush – as a vibratory device to reduce the pain of injections (1). This may sound quirky and a slightly worrisome use for a toothbrush (particularly if it is going to be used for cleaning teeth afterwards). However, the authors conclude it to be a novel device which can help reduce injection anxiety and pain but also distract the patient by giving them something to talk about whilst having the procedure. The process is very simple - the head of the toothbrush is covered with a disposable glove, switched on and then applied with the bristles of the head facing onto the skin, as close as possible to the site of the injection. Once the procedure is over the glove is discarded and the toothbrush can be reused.
How effective is vibration as an analgesic?
The utility of vibration as a cutaneous pain reducing modality has been explored in research over the years, particularly for treatments involving young children. McGinnis (2) showed in an randomised study that using a simple vibratory device on neonates whilst having their heels pricked, reduced distress compared to those treated without vibration. Similarly, the use of Buzzy® - a colourful distracting vibratory tool reduced the children’s anxiety undergoing IV insertions (3). However, other studies have disagreed with the findings and suggest it makes little difference when compared with other distraction measures in children (4).
In adult populations the use of vibration has also been investigated with mixed results. A study in 2017 by Guney (5) demonstrated how vibration applied through a device applied to patients undergoing lip fillers demonstrated efficacy at reducing overall pain levels in 25 patients. Similarly, patients undergoing Botox injections in their forehead preferred the use of a vibratory device in a study where half of the forehead was injected without vibration and the other half with(6). This however, has been countered by other work suggesting there is no advantage to the use of vibration as an analgesic (7) in facial procedures.
The science at first glance may seem simple enough. Is the effect just distracting or truly pain modulating? If one applies the concept to the Melzack and Wall’s 1965 pain gate theory where application of vibratory stimulation (through Aβ fibres) stimulate interneurons in the spinal cord. This ultimately down regulates the activity in the pain conducting Aɗ and C fibres which could explain the effect. However, this theory may over simplify the complexity of pain and its perception as recent experiments have shown and the modulating effect may actually be occurring higher up - in the sensory cortex of the brain itself (8).
The bottom Line
For the moment, we still don’t know if vibration analgesia is truly helpful or not. Patient reported studies to date have given mixed reports. However, is there something we are missing in the research? For example, studying the variation of the vibratory intensity or frequency to see if it makes any difference for surface pain relief. But for the moment, an old electric toothbrush maybe worth a try in the clinic – if nothing else it is a good distraction and talking point for the patient to take their mind off the injection.
1. Duplisea MJ, Flores K. Buzzing away the pain: Using an electric toothbrush for vibration anesthesia during painful procedures. Pediatr Dermatol. 2019;36(3):414-5.
2. McGinnis K, Murray E, Cherven B, McCracken C, Travers C. Effect of Vibration on Pain Response to Heel Lance: A Pilot Randomized Control Trial. Adv Neonatal Care. 2016;16(6):439-48.
3. Moadad N, Kozman K, Shahine R, Ohanian S, Badr LK. Distraction Using the BUZZY for Children During an IV Insertion. J Pediatr Nurs. 2016;31(1):64-72.
4. Benjamin AL, Hendrix TJ, Woody JL. Effects of Vibration Therapy in Pediatric Immunizations. Pediatr Nurs. 2016;42(3):124-9; discussion 30.
5. Guney K, Sezgin B, Yavuzer R. The Efficacy of Vibration Anesthesia on Reducing Pain Levels During Lip Augmentation: Worth the Buzz? Aesthet Surg J. 2017;37(9):1044-8.
6. Sharma P, Czyz CN, Wulc AE. Investigating the Efficacy of Vibration Anesthesia to Reduce Pain From Cosmetic Botulinum Toxin Injections. Aesthet Surg J. 2011;31(8):966-71.
7. Chorney SR, Villwock JA, Suryadevara AC. Vibration Versus Ice to Reduce Cosmetic Botulinum Toxin Injection Pain-A Randomized Controlled Trial. Ear Nose Throat J. 2019:145561319839839.
8. Hollins M, McDermott K, Harper D. How Does Vibration Reduce Pain? Perception. 2014;43(1):70-84.