Viral illness with petechial rash

Created Oct 2015
Reviewed Dec 2019


Should petechial rash be coded as an additional diagnosis when documented with viral illness or can it be treated as a typical symptom of the viral illness? If it should be coded, is R21 Rash and other nonspecific skin eruption or R23.3 Spontaneous ecchymoses the most appropriate code?


The presence of a petechial rash with a viral illness/infection is a common symptom.  However, in some cases a petechial rash may be an indication of a more serious condition and requires further investigations.  Therefore, where the petechial rash meets ACS 0002 Additional diagnoses criteria it should be coded in addition to the viral illness.

Assign R23.3 Spontaneous ecchymoses for documentation of petechial rash and use free text to specify the condition.

Where the petechial rash does not meet ACS 0002 Additional diagnoses criteria use free text on the viral illness code descriptor to specify the rash for example, B34.9 Viral Illness with petechial rash on both hands.

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