ICD-10 Code A51.39 – Other secondary syphilis of skin (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A51.39 – Other secondary syphilis of skin
What it is
This code identifies secondary syphilis with skin involvement that does not fit a more specific secondary syphilis skin code. It reflects a systemic treponemal infection presenting with cutaneous findings.
Clinical signs
Typical findings include a generalized rash, mucocutaneous lesions, or other skin manifestations of secondary syphilis. Clinical features vary; refer to documentation.
When to use this code
Use A51.39 when the provider documents secondary syphilis affecting the skin and does not specify a more exact subtype. It may apply when the record notes skin lesions, rash, or other secondary syphilitic skin findings. Check documentation if the site or stage is unclear.
Do not use for
Do not use this code for primary syphilis, latent syphilis, or tertiary syphilis. Do not use it when the documentation supports a more specific secondary syphilis code.
Coding tip
Code the documented stage and manifestation exactly; if the skin finding is not clearly linked to secondary syphilis, query the provider.