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Herpes simplex - oral - Making a diagnosis
Recurrent disease

  • Recurrent herpes simplex type 1 (HSV-1) infections can be triggered by a number of factors, including fatigue, bright sunlight, trauma, and menstruation [Worrall, 2006; Gonsalves et al, 2007; Woo and Challacombe, 2007].
  • Recurrences of HSV-1 infection are often shorter and less severe than the initial attack and usually present as cold sores at the border between the lip and skin of the face [Worrall, 2006; Torres, 2007]. It is rare for recurrent episodes of gingivostomatitis to occur; this usually only happens if the person has reduced immunity [Esmann, 2001].
  • Diagnosis of recurrent cold sores is usually clinical, based on the lesions and lack of systemic symptoms [Bentley et al, 2003].
  • Prodromal symptoms last between 6 and 48 hours and include pain, burning, tingling, itching, and paraesthesia.
  • Pain is usually most severe up to 24 hours after the lesions appear, but resolves over 4–5 days.
  • Signs [Hirsch, 1995; Bentley et al, 2003; Kolokotronis and Doumas, 2006; Torres, 2007; Woo and Challacombe, 2007]:
    • Vesicles appear at the border of the outer lip between the lip and the skin (more commonly the lower lip) and may occur at the same site for each recurrence.
    • Ulceration and crusting of vesicles usually occurs within 48 hours.
    • Usually lesions are less than 100 mm2 in area.
    • Systemic complications are not usually associated with recurrent oral infections, but local lymphadenopathy may be seen.
  • Recurrent HSV infection in people who are immunocompromised is often atypical and may present as single or multiple ulcers anywhere in the oral cavity, which may be large, progressive, and persistent [Woo and Challacombe, 2007].
  • Tests are not usually necessary in immunocompetent people, as history and examination will usually confirm the diagnosis.
    • Herpes simplex virus can be detected, and the type determined, using viral culture from skin vesicles. Early in the infection, 80–90% of viral cultures from untreated lesions are positive, but the false-negative rate increases 2 days after the lesions have appeared [Torres, 2007].
    • Polymerase chain reaction (PCR) is an alternative diagnostic test, which in general detects HSV 3–4 times more often than cultures [Esmann, 2001; Woo and Challacombe, 2007].
    • The availability of tests may vary in primary care, therefore check with the local laboratory.

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