ICD-10 Code B08.3 – Erythema infectiosum [fifth disease] (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B08.3 – Erythema infectiosum [fifth disease]
What it is
B08.3 identifies erythema infectiosum, also called fifth disease, a common viral illness caused by parvovirus B19. It is usually self-limited and most often affects children, but you may see it in adults too.
Clinical signs
Typical findings include mild fever, upper respiratory symptoms, and the classic “slapped cheek” facial rash, followed by a lacy rash on the trunk or limbs. Clinical features vary; refer to documentation.
When to use this code
Use B08.3 when the provider documents erythema infectiosum, fifth disease, or parvovirus B19 infection with the characteristic rash. It is appropriate when the diagnosis is established clinically or documented as the reason for the visit. Check documentation if the note only mentions exposure or nonspecific viral rash.
Do not use for
Do not use this code for nonspecific viral exanthems, rubella, measles, or other rash illnesses without documentation of erythema infectiosum. If the record does not clearly support fifth disease, check documentation.
Coding tip
Code B08.3 only when the chart clearly names fifth disease or erythema infectiosum; do not infer it from rash alone.