American Board of Internal Medicine (ABIM) Certification Practice Exam

Which therapy is first-line for post-herpetic neuralgia?

1. Topical lidocaine

2. Acetaminophen

3. Narcotic analgesics

4. Gabapentin

The correct answer is: Topical lidocaine

The first-line therapy for post-herpetic neuralgia is topical lidocaine. This topical agent works by blocking sodium channels and providing localized pain relief, making it particularly effective for the neuropathic pain that can arise after a shingles (herpes zoster) infection. The advantage of using a topical treatment is that it can specifically target the painful area while minimizing systemic side effects often seen with oral medications. In post-herpetic neuralgia, patients typically experience burning, itching, and significant discomfort in the affected dermatomes long after the rash has healed. Topical lidocaine can offer immediate pain relief to these specific areas, allowing patients to manage their symptoms more effectively. Gabapentin is another effective treatment for neuropathic pain and is frequently used in practice; however, it is typically not considered the first-line treatment for post-herpetic neuralgia compared to topical agents. Similarly, while narcotic analgesics can help manage pain, they are not recommended as a first-line treatment due to potential risks of dependency and also generally less effectiveness specifically for neuropathic pain. Acetaminophen is also less effective for the type of pain associated with post-herpetic neuralgia compared to more targeted therapies. Therefore, the use of topical