What is the medical term for an oral fever blister?

Herpes Labialis: The Medical Term for Oral Fever Blisters

The medical term for an oral fever blister is herpes labialis, which is primarily caused by herpes simplex virus type 1 (HSV-1) infection 1.

Clinical Features and Pathophysiology

• Herpes labialis is a common skin infection worldwide characterized by recurrent episodes of painful, vesicular eruptions primarily on the lips and perioral skin 2
• The virus establishes latency in the sensory ganglia (trigeminal ganglia) after primary infection and can reactivate later, causing recurrent episodes 1
• Reactivation stimuli include exposure to ultraviolet light, fever, psychological stress, and menstruation 1
• The condition is highly contagious and can cause significant discomfort, pain, and adverse effects on quality of life 2

Clinical Progression

• The prodromal phase is associated with itching, burning, and/or paresthesia prior to visible lesions 1
• Clinical progression evolves through several stages 1:
  • Initial erythema and papule formation
  • Development of vesicles (fluid-filled blisters)
  • Pustulation
  • Ulceration
  • Scabbing and healing
• Peak viral titers occur in the first 24 hours after lesion onset, when most lesions are in the vesicular stage 1

Epidemiology

• HSV-1 is traditionally acquired in childhood and adolescence through non-sexual contact 1
• At least 50% of new cases of herpes genitalis in developed countries are now caused by HSV-1 1
• Higher socioeconomic status is associated with a lower prevalence of HSV-1 1
• Risk factors include female gender, older age (65-74 years), white race/ethnicity, frequent upper respiratory infections, and low lymphocyte counts 1
• Interestingly, smokers report fewer herpes labialis outbreaks than nonsmokers 1

Diagnosis

• Diagnosis of herpes labialis is primarily clinical, based on the characteristic appearance of grouped lesions (papules, vesicles, ulcers) on the lip 3, 2
• Laboratory confirmation may be required in immunocompromised patients if the clinical presentation is atypical 1
• When in doubt, polymerase chain reaction (PCR) testing can be performed for definitive diagnosis 3

Treatment Options

Antiviral Therapy

• The aim of antiviral therapy is to block viral replication to shorten symptom duration and accelerate healing 1
• Treatment should be initiated as soon as possible, ideally in the prodromal stage and no later than 48 hours from onset of lesions 2
• FDA-approved treatments include 4:
  • Valacyclovir (Valtrex) for treatment of cold sores in adults and pediatric patients ≥12 years
  • Oral valacyclovir 2 grams twice daily on Day 1 followed by 1 gram twice daily on Day 2 can shorten the duration of cold sore episodes by about 1 day compared to placebo 4

Topical Treatments

• Topical antiviral agents include 5% acyclovir cream/ointment (Zovirax) ± hydrocortisone (Xerese), 1% penciclovir (Denavir) cream 2
• For mild symptoms, topical zinc sulfate/zinc oxide and analgesics (systemic or topical lidocaine) may be sufficient 3
• Application of a bland emollient such as 50% white soft paraffin and 50% liquid paraffin is recommended to support barrier function and encourage re-epithelialization 1

Chronic Suppressive Therapy

• For patients with severe or frequent (six or more episodes per year) recurrences, chronic suppressive therapy with oral antiviral agents should be considered 2
• Oral antivirals are the treatment of choice for chronic daily suppressive therapy 2

Prevention and Management of Recurrences

• Application of sunscreen or zinc oxide may help decrease the probability of recurrent outbreaks 1
• Avoid triggers when possible (UV light exposure, stress) 1
• Maintain good oral hygiene with warm saline mouthwashes to reduce bacterial colonization 5

Important Considerations

• Treatment efficacy is significantly improved when initiated early in the course of an outbreak, preferably during the prodromal phase 1, 2
• Herpes labialis remains latent and can recur; there are no treatments that can eliminate the virus completely 3
• For immunocompromised patients, episodes are usually longer and more severe, potentially involving the oral cavity or extending across the face 1
• Proper blister management includes gently cleansing with antimicrobial solution, piercing the blister at the base with a sterile needle, and allowing drainage while keeping the blister roof intact as a biological dressing 1

Herpes labialis represents a significant burden for affected individuals due to its recurrent nature and potential impact on quality of life. Early recognition and prompt treatment are essential for optimal management of this common condition.