ICD10
ICD-10 Code A51.4: Other secondary syphilis
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Certain infectious and parasitic diseases (A00-B99).
When is it used?
- May be used when a clinician documents other secondary syphilis in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
- This entry may represent a broader category rather than the most specific billable code.
Code hierarchy
chapter
1Certain infectious and parasitic diseases (A00-B99)
block
A50-A64Infections with a predominantly sexual mode of transmission
category
A51Early syphilis
currentA51
Where you may see this code
You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.
Related specialists
Infectious Disease SpecialistGeneral Physician
Related codes
A51.41Secondary syphilitic meningitiscodeA51.42Secondary syphilitic female pelvic diseasecodeA51.43Secondary syphilitic oculopathycodeA51.44Secondary syphilitic nephritiscodeA51.45Secondary syphilitic hepatitiscodeA51.46Secondary syphilitic osteopathycodeA51.49Other secondary syphilitic conditionscode
Sibling codes
Mapped diagnoses and classifications
SNOMED_CT 186863009high
Acute secondary syphilitic meningitis
Source: SNOMED International ICD-10 map
SNOMED_CT 68863007high
Acute syphilitic meningitis
Source: SNOMED International ICD-10 map
SNOMED_CT 240565001high
Asymptomatic secondary neurosyphilis
Source: SNOMED International ICD-10 map
SNOMED_CT 15993471000119105high
Bilateral iritis due to secondary syphilis
Source: SNOMED International ICD-10 map
SNOMED_CT 15679681000119101high
Bilateral iritis of eyes caused by Treponema pallidum
Source: SNOMED International ICD-10 map
SNOMED_CT 15685441000119102high
Bilateral retinitis of eyes caused by Treponema pallidum
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
A51.4
Replacement codes
A51.41 — Secondary syphilitic meningitisA51.42 — Secondary syphilitic female pelvic diseaseA51.43 — Secondary syphilitic oculopathyA51.44 — Secondary syphilitic nephritisA51.45 — Secondary syphilitic hepatitisA51.46 — Secondary syphilitic osteopathyA51.49 — Other secondary syphilitic conditions
Common synonyms
Other secondary syphilis
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.