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Herpes Simplex A024

Last amended 
26 June 2015
Current RMA Instruments:
Reasonable Hypothesis SOP
3 of 2010
Balance of Probabilities SOP
4 of 2010
Changes from Previous Instruments:

SOP Bulletin 140

ICD Coding:
  • ICD-9-CM Codes: 054
  • ICD-10-AM Codes: A60, B00

This SOP covers illnesses caused by both Herpes simplex type 1 and Herpes simplex type 2.  Identifying the clinical onset for herpes infection can be difficult.  In certain circumstances this SOP may be applied twice.  See comments below.

Is specific evidence required to apply the SOPNo.
Are there SOP factors that require specific diagnostic information? – Yes.

There are a number of factors that apply only to specific sites of infection.

Additional diagnoses covered by SOP
  • Cold sores
  • Genital herpes
  • Herpes gladiatorum
  • Herpes simplex encephalitis
  • Herpes simplex retinal necrosis
  • Herpes simplex type 1 (HSV-1)
  • Herpes simplex type 2 (HSV-2)
  • Herpetic whitlow
  • Oral-facial herpes
Conditions not covered by SOP
  • Herpes zoster, ICD 9 code 053

The following investigations may be useful in establishing the diagnosis.

  • Serology testing can be performed but is not done routinely.

Both infections are common.  Initial infection tends to cause a significant clinical illness but it may be asymptomatic or go unrecognised (e.g. HSV-1 pharyngitis may be mistaken for a bacterial pharyngitis.  HSV-1 is more common and tends to be acquired earlier, via contact with oral secretions.  HSV-2 is usually acquired from sexual contact.  Both infections tend to cause recurrent clinical episodes, particularly in the first year after infection.

HSV-1 typically causes oral-facial infection.  Recurrent episodes most commonly involve the lips (cold sores). HSV-2 typically causes genital infection.  However, both may affect either site and both may manifest at other sites.  Infection may remain dormant for many years then be reactivated by some trigger factor.

Both infections may occur in one person.  Whether a new clinical episode is a recurrence or a new infection with the other HSV type may be difficult to determine.  In such cases medical advice should be sought.  It may be the case that the SOP needs to be applied twice – once to cover onset or worsening of HSV-1 and again to cover onset or worsening of HSV-2.