Shingles Appearance and First-Line Treatment
The first-line treatment for shingles (herpes zoster) is oral antiviral therapy with valacyclovir 1000 mg three times daily, famciclovir 500 mg three times daily, or acyclovir 800 mg five times daily for 7 days, ideally started within 72 hours of rash onset. 1, 2
Clinical Appearance of Shingles
Shingles has a characteristic appearance and progression:
- Prodromal phase: Patients may experience malaise, headache, low-grade fever, and abnormal skin sensations (tingling, burning, itching) for 2-3 days before the rash appears 2
- Rash characteristics:
- Unilateral distribution, confined to a single dermatome
- Begins as a maculopapular rash
- Progresses to clear vesicles that become cloudy
- Vesicles eventually crust over in 7-10 days 2
- Typically follows a dermatomal distribution (most commonly thoracic, cervical, or ophthalmic)
First-Line Antiviral Treatment
Antiviral therapy should be initiated as soon as possible, ideally within 72 hours of rash onset:
Recommended Regimens:
- Valacyclovir: 1000 mg orally three times daily for 7 days 3
- Famciclovir: 500 mg orally three times daily for 7 days 4, 5
- Acyclovir: 800 mg orally five times daily for 7 days 2
Clinical Considerations:
- Valacyclovir and famciclovir are preferred over acyclovir due to less frequent dosing and better bioavailability 6, 3
- For severe cases requiring hospitalization, intravenous acyclovir 5-10 mg/kg every 8 hours for 5-7 days is recommended 1
- For acyclovir-resistant strains in severe cases, consider foscarnet 40 mg/kg IV every 8 hours 1
Dosage Adjustments for Renal Impairment:
Adjust antiviral dosage based on creatinine clearance:
For acyclovir 800 mg:
- CrCl >25 mL/min: 800 mg every 4 hours, 5 times daily
- CrCl 10-25 mL/min: 800 mg every 8 hours
- CrCl 0-10 mL/min: 800 mg every 12 hours 1
Pain Management
Pain control is an essential component of shingles treatment:
- Mild pain: Acetaminophen or NSAIDs 1
- Moderate to severe pain: Consider:
- Gabapentin (titrate to 2400 mg per day in divided doses)
- Pregabalin
- Tricyclic antidepressants 1
- Topical options: Lidocaine patches or capsaicin 8% dermal patch/cream for peripheral neuropathic pain 1, 2
Prevention of Postherpetic Neuralgia (PHN)
Postherpetic neuralgia is the most common complication of shingles, occurring in about 20% of patients 2:
- Early antiviral therapy reduces the risk and duration of PHN 5, 3
- Valacyclovir and famciclovir have been shown to reduce the duration of PHN more effectively than acyclovir 6, 5, 3
- For established PHN, treatment focuses on symptom control with gabapentin, pregabalin, tricyclic antidepressants, and topical agents 2
Patient Education and Follow-up
- Advise patients to avoid close contact with others during active lesions to prevent transmission 1
- Re-examine patients 3-7 days after treatment initiation to assess response 1
- Consider alternative diagnoses or treatment approaches if no improvement occurs 1
- Vaccination with the herpes zoster vaccine is recommended for adults 50 years and older to prevent future outbreaks 1
Common Pitfalls and Caveats
- Delayed treatment: Starting treatment beyond 72 hours after rash onset is still beneficial, especially for reducing pain duration 6
- Inadequate dosing: Using lower than recommended doses may lead to treatment failure
- Missing ophthalmic involvement: Always check for eye involvement, which requires prompt ophthalmology referral
- Overlooking immunocompromised status: Immunocompromised patients may require longer treatment duration and closer monitoring 1
- Inadequate pain management: Pain control should be addressed from the beginning of treatment