From the Guidelines
The best numbing cream for most people is EMLA (lidocaine 2.5% and prilocaine 2.5%), which provides effective topical anesthesia for procedures like injections, blood draws, or minor skin procedures. This is based on the most recent and highest quality study available, which found that EMLA cream provides excellent topical anesthesia for laceration repair and other minor procedures 1.
Key Points to Consider
- Apply a thick layer to clean, dry skin and cover with an occlusive dressing for 60-90 minutes before the procedure for maximum effect.
- For faster onset, LMX-4 or LMX-5 (4% or 5% lidocaine) works in about 30 minutes, as noted in a study on the relief of pain and anxiety in pediatric patients 1.
- These creams work by blocking sodium channels in nerve cells, preventing pain signals from being transmitted to the brain.
- For sensitive areas like the face or genitals, use lower concentrations and shorter application times.
- People with certain medical conditions (liver disease, heart problems) or those taking specific medications should consult a healthcare provider before use, as cautioned in a study on the guidelines for the use of local anesthesia in office-based dermatologic surgery 1.
Important Considerations
- Side effects are typically mild and include temporary skin redness, paleness, or slight swelling at the application site.
- Avoid applying to broken skin, mucous membranes, or large body areas unless specifically directed by a healthcare provider.
- It is also important to note that non-cocaine anesthetics are preferred over those containing cocaine for use in office-based dermatologic surgery due to the increased cost and potential for adverse events 1.
From the Research
Topical Anesthetics for Dermatologic Procedures
The choice of numbing cream depends on various factors, including the type of procedure, individual patient needs, and desired onset of action. Several studies have compared the efficacy and safety of different topical anesthetics:
- A study published in 2013 2 reviewed the use of lidocaine/tetracaine cream as a topical anesthetic for dermatologic laser procedures, highlighting its effective pain alleviation and favorable profile.
- Another study from 2010 3 evaluated the safety and efficacy of a rapid-acting topical 4% lidocaine gel, finding that it produced significant anesthesia without occlusion in approximately 25-30 minutes.
- A comparison of five commonly-available lidocaine-containing topical anesthetics 4 found significant interindividual differences in serum levels of lidocaine and its metabolite, emphasizing the need for cautious use under healthcare professional supervision.
Comparison of Topical Anesthetics
Studies have also compared the efficacy of different topical anesthetics:
- A randomized, double-blinded, split-face study 5 compared the efficacy of lidocaine 4% and benzocaine 20% with compounded lidocaine 23%/tetracaine 7% for discomfort mitigation during microfocused ultrasound with visualization treatment, finding similar pain scores and numbness scores for both products.
- A study published in 2013 6 compared the vasoconstrictor effect of two topical anesthetics, finding that 4% liposomal lidocaine had a relatively minor vasoconstrictor effect and achieved an anesthetic effect in 30 minutes, making it more suitable for cosmetic dermatologic procedures.
Key Findings
Key findings from these studies include:
- Lidocaine/tetracaine cream is an effective topical anesthetic for dermatologic laser procedures 2.
- Topical 4% lidocaine gel produces significant anesthesia without occlusion in approximately 25-30 minutes 3.
- Interindividual differences in serum levels of lidocaine and its metabolite emphasize the need for cautious use under healthcare professional supervision 4.
- Lidocaine 4% and benzocaine 20% are effective for discomfort mitigation during microfocused ultrasound with visualization treatment 5.
- 4% liposomal lidocaine has a relatively minor vasoconstrictor effect and achieves an anesthetic effect in 30 minutes, making it suitable for cosmetic dermatologic procedures 6.