From the Guidelines
Topical analgesics, such as benzocaine 20% or lidocaine 5%, can effectively relieve pain from cold sores (herpes labialis) by numbing the nerve endings. According to the most recent and highest quality study available, which examined the use of local anesthesia in office-based dermatologic surgery 1, benzocaine and lidocaine are effective topical anesthetics for relieving pain. The study found that benzocaine has an onset of 5 minutes and a duration of 15-45 minutes, while lidocaine has an onset of 2 minutes and a duration of 30-45 minutes.
When considering treatment options for cold sores, it is essential to prioritize morbidity, mortality, and quality of life as the outcome. In this case, topical analgesics can improve quality of life by providing temporary pain relief. However, it is crucial to note that these analgesics only address pain and do not treat the underlying viral infection or speed healing.
Some key points to consider when using topical analgesics for cold sores include:
- Applying the analgesic at the first sign of tingling or burning (prodromal phase) and continuing until the sore heals, typically within 7-10 days
- Using benzocaine 20% or lidocaine 5% up to 4 times daily for temporary pain relief
- Considering alternative options, such as over-the-counter products containing camphor and phenol, for mild pain relief and moisturizing
- Combining pain relief with antiviral treatments, like acyclovir or docosanol, for complete management of cold sores, as suggested by studies on the management of herpes labialis 1.
Overall, the use of topical analgesics, such as benzocaine 20% or lidocaine 5%, can be an effective way to relieve pain from cold sores, and their use should be considered in conjunction with antiviral treatments for optimal management of the condition.
From the FDA Drug Label
PRINCIPAL DISPLAY PANEL - 77 g Bottle Carton TopCare® health COMPARE TO ICY HOT® ACTIVE INGREDIENTS* MAXIMUM STRENGTH LIDOCAINE Cold & Hot Pain Relieving Lidocaine Cream 4% Lidocaine • 1% Menthol LIDOCAINE 4% / TOPICAL ANALGESIC MENTHOL 1% / TOPICAL ANALGESIC Helps to Numb Away Pain Non-Greasy Maximum Strength External Analgesic with 4% Lidocaine Directions Adults and children over 12 years: ◆ Apply to affected area not more than 3 to 4 times daily ◆ AFTER APPLYING, WASH HANDS WITH SOAP AND WATER children under 12 years or younger: ask a doctor
Lidocaine 4% cream can be used as a topical analgesic for cold sores, as it is indicated for cold and hot pain relief 2. The directions for use state that it can be applied to the affected area not more than 3 to 4 times daily for adults and children over 12 years 2.
- Key points:
- Apply to affected area
- Not more than 3 to 4 times daily
- For adults and children over 12 years
- Children under 12 years or younger should ask a doctor 2
From the Research
Topical Analgesia for Cold Sores
- Topical analgesics can provide relief for acute and chronic pain with minimal adverse systemic effects 3
- Lidocaine is a commonly studied topical analgesic, with strong evidence supporting its use in treating postherpetic neuralgia and diabetic neuropathy 3, 4, 5
- Topical lidocaine has been approved for the treatment of post-herpetic neuralgia and has shown efficacy in other pain conditions, including lower back pain, carpal tunnel syndrome, and osteoarthritis joint pain 4, 5
- A study on herpes labialis found that topical formulations containing lidocaine and prilocaine decreased pain and showed antiviral properties, making them a potential treatment option for cold sores 6
- Another study on wound pain relief found that 5% lidocaine hydrochloride cream significantly decreased pain intensity and showed high safety and tolerability 7
Mechanism of Action
- Topical lidocaine works by targeting peripheral nociceptive pathways and minimizing absorption into the plasma, reducing the risk of systemic adverse effects 4
- The penetration of lidocaine into the skin produces an analgesic effect without producing a complete sensory block 4