# Herpes labialis (cold sores)

- Category: infectious
- Review status: reviewed (every claim checked against a document named on this page)
- Sources: Egyptian National Drug Formulary - Antimicrobial 2023 (acyclovir monograph)
- Verified date: 2026-08

## Verified against

- Egyptian National Drug Formulary - Antimicrobial 2023 (acyclovir monograph)

## Treatment metadata

- Acyclovir — topical

## Complete treatment card

```text
HERPES LABIALIS (COLD SORES)
Sources: Egyptian National Drug Formulary - Antimicrobial 2023 (acyclovir monograph)
Review status: REVIEWED against the source listed above  (2026-08)

IS IT THIS? - reference only, to read alongside your own examination
  SYMPTOMS - what the patient reports (6)
    - Most oral HSV-1 infection causes no symptoms; when it does, the usual result is a cold sore
    - A first attack starts three days to a week after exposure
    - Before the blisters there is a prodrome of malaise, no appetite, fever, sore glands, and local
      pain, tenderness, burning or tingling  [blisters · fever · local tenderness · malaise ·
      tingling]
    - In children a first attack often takes the form of gingivostomatitis with pain, bad breath and
      difficulty swallowing  [difficulty swallowing]
    - In adults it can look like pharyngitis or a glandular-fever-like illness  [fever]
    - Recurrences are milder, heralded by about a day of tingling, burning and itch  [itching ·
      relapse · tingling]
  SIGNS - what you find (12)
    - First attack sits on the mouth and lips: painful clustered blisters on a red base with a
      scalloped edge, becoming pustules, erosions and ulcers  [blisters · pustules]
    - Lesions crust and the episode settles within 2 to 6 weeks
    - Recurrent attacks classically sit on the lip margin, not spread across the mouth and lips as
      the first one does
    - Herpetic sycosis: beard-area follicular papules with erosion in a man who shaves closely, from
      scattered spots to the whole beard, clearing in 2 to 3 weeks  [papules]
    - Herpes gladiatorum: lesions on the side of the neck and face and on the forearms 4 to 11 days
      after contact, easily mistaken in athletes for bacterial folliculitis
    - Herpetic whitlow: deep blisters on a finger or around the nail that erode, often mistaken for
      acute paronychia or blistering dactylitis  [blisters]
    - Whitlow can enlarge elbow or armpit nodes with red streaking that imitates cellulitis
      [cellulitis]
    - Eye disease: keratoconjunctivitis in one or both eyes with tearing, lid swelling, light
      sensitivity, a swollen conjunctiva and a node in front of the ear  [eye discharge · eyelid
      swelling · photophobia]
    - A branching dendritic corneal ulcer is diagnostic of ocular herpes, and this keratitis is a
      leading cause of blindness  [loss of vision]
    - Red flag: strange behaviour, focal temporal-lobe signs, fever and altered consciousness
      suggest herpes encephalitis, fatal in over 70% untreated  [fever]
    - Eczema herpeticum: widespread punched-out erosions of 2 to 3 mm with bloody crusts, on skin
      already damaged by eczema or similar disease
    - Newborn herpes shows at day 5 to 14 on scalp and trunk, may spread over the skin and to mouth
      and eye, and brain involvement brings lethargy, poor feeding, a bulging fontanelle,
      irritability and fits  [bulging fontanelle · irritability · lethargy · poor feeding ·
      seizures]
  TESTS (3)
    - Antibody testing by western blot is the reference standard, while viral PCR is the most
      sensitive and specific method
    - Other options are viral culture, direct fluorescent antibody and Tzanck smear
    - A Tzanck smear only shows multinucleated giant cells and cannot separate herpes simplex from
      varicella zoster; the fluorescent antibody test can
  IF NOT THIS - what else fits (6)
    - Aphthous stomatitis
    - Stevens-Johnson syndrome
    - Erythema multiforme major
    - Herpangina
    - History and examination are what separate these from oral herpes
    - For a finger lesion: blistering dactylitis, and acute or chronic paronychia
  Source  StatPearls "Herpes Simplex Type 1" - disease-level clinical article
  Status  traced to the source above

1. ACYCLOVIR                                              [1st line]
   Adult    Apply 5 times daily (every 4 hours) to affected skin x 4 days
   Peds     Topical cream: Apply 5 times daily for 4 days in immunocompetent children ≥12 years of
            age
   Source   Egyptian National Drug Formulary - Antimicrobial 2023 (acyclovir monograph)
   Why      Nucleoside analogue antiviral that is selectively activated in infected cells to block
            viral DNA replication, applied topically at the first sign of a cold-sore recurrence to
            shorten the episode.
   Caution  Apply at first sign of prodromal tingling or redness.
            Wash hands before and after application to prevent autoinoculation.
            Avoid contact with eyes.
   Egypt    VIRUSTAT 5% CREAM 5 GM           PHAROPHARMA         13.00 EGP
            ACYCLOSTAD 5% CREAM 10 GM        GLOBAL NAPI P...    23.00 EGP
            ACYCLOVIR-MISR 5% TOPICAL CREAM 10 GM MISR                                     23.00 EGP
            VIRUSTAT 5% CREAM 10 GM          PHAROPHARMA         23.00 EGP
            ZOVIRAX 5% TOPICAL CREAM 10 GM   GLAXO SMITHKLINE    27.00 EGP

Prices are indicative (dataset snapshot 2026-06); verify with the pharmacy.
```

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Dawaa Reference is a reference for prescribers, not a medical device, and does not replace clinical judgement.

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