Herpes labialis

Background

• Cause of the common "cold sore"
• Sores typically heal within 2–3 weeks, but the herpes virus remains dormant in the facial nerve branches, following orofacial infection, periodically reactivating (in symptomatic people) to create sores in the same area of the mouth or face at the site of the original infection.
  • Frequency varies from rare episodes to 12 or more recurrences per year (typically 1-3 attacks per year)
  • The frequency and severity of outbreaks generally decreases over time.

Clinical Features

Herpes labialis

• typically umbilicated vesicles, painful, that unroof and crust over
• typically localized to the vermillion border

Classic Phases

• Prodromal (day 0–1): Tingling, itching, and reddening of the skin around the infected site
• Inflammation (day 1): Swelling and redness
• Pre-sore (day 2–3): Tiny, hard, inflamed papules and vesicles that may itch and are painfully sensitive to touch.
• Open lesion (day 4): Vesicles break open and merge to create one big, open, weeping ulcer. May develop a fever and lymphadenopathy
• Crusting (day 5–8): A honey/golden crust starts to form from the syrupy exudate.
• Healing (day 9–14): New skin begins to form underneath the scab. A series of scabs will form over the sore (called Meier Complex), each one smaller than the last. Irritation, itching, and some pain are common.
• Post-scab (12–14 days): A reddish area may linger at the site of infection.

Differential Diagnosis

Herpes Simplex Virus-1

• Eczema herpeticum
• Herpes gingivostomatitis
• Herpes keratitis
• Herpes labialis (cold sore)
• Herpes simplex encephalitis
• Herpetic whitlow

Diagnosis

• Typically clinical

Management

Anti-viral Treatment

Normal Host

• Options:
  • Acyclovir
    • Acyclovir 400 mg PO 5x/day (q4hrs while awake) x 5 days OR
    • Acyclovir 40-80mg/kg PO divided in 3-4 doses for 5-7 days OR
    • Can also be used as topical cream 5x per day
  • Famciclovir 500mg PO BID x 7 days OR
  • Valacyclovir 2g PO q12h x 1 day

Immunocompromised

• Options:
  • Acyclovir
    • Acyclovir 5 mg/kg IV q8h x 7 days OR
    • Acyclovir 400mg PO 5x/day x 14-21 days
  • Famciclovir 500mg PO BID x 7 days OR
  • Valacyclovir 500mg PO BID x 5-10 days