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.
• Treatment does not affect dormant virus in nerve ganglions → recurrent disease remains possible

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

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

Oral rashes and lesions

• Angioedema
• Aphthous stomatitis
• Herpes gingivostomatitis
• Herpes labialis
• Measles (Koplik's spots)
• Perioral dermatitis
• Oral thrush
• Steven Johnson syndrome
• Strep pharyngitis

Evaluation

• Clinical diagnosis, based on history and physical exam
• Available laboratory studies (not required for diagnosis):
  • Viral culture (gold standard)
  • Direct immunofluorescence
  • Tzanck smear (poor specificity)

Management

Anti-viral Treatment

Normal Host

• Options:
  • Acyclovir
    • 400 mg PO 5x/day (q4hrs while awake) x 5 days, OR
    • 40-80mg/kg PO divided in 3-4 doses for 5-7 days, OR
      • Can also be used as a cream or oral suspension (swish and swallow)
  • Famciclovir 500mg PO BID x 7 days, OR
  • Valacyclovir 2gm PO q12 x 1 day

Immunocompromised

• Options:
  • Acyclovir
    • 5 mg/kg IV (over 1 hours) q8h x 7 days, OR
    • 400mg PO 5x/day x 14-21 days
  • Famciclovir 500mg PO BID x 7 days, OR
  • Valacyclovir 500mg PO BID x 5-10 days

Disposition

• Discharge if uncomplicated
• Consider admission if immunocompromized, critically ill, or with large necrotic ulcers

See Also

• Herpes Simplex Virus-1
• Oropharynx and jaw diagnoses

References

Authors

Ross Donaldson, Michael O'Brien, MD, Daniel Ostermayer, Neil Young