2026 ICD-10-CM Diagnosis Code A51.39Other secondary syphilis of skin
ICD-10-CM Codes›A00–B99›A50-A64›A51
- Billable — Valid for Submission
- Not Chronic
A51.39 is a billable ICD-10-CM diagnosis code for other secondary syphilis of skin. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 606 through 607. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sexually transmitted infections (excluding HIV and hepatitis) and Skin and subcutaneous tissue infections.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acquired syphilis
- Anal mucosa finding
- Corona veneris
- Lues maligna
- Macular eruption
- Macular syphilide
- Oral syphilis
- Papular syphilide
- Pustular syphilide
- Rash of secondary syphilis
- Secondary syphilis of anus
- Secondary syphilis of digestive system
- Secondary syphilis of mouth
- Secondary syphilis of mucous membrane
- Secondary syphilis of pharynx
- Secondary syphilis of skin
- Secondary syphilis of skin and mucous membrane
- Secondary syphilis of tonsil
- Secondary syphilis of vulva
- Syphilitic leukoderma
- Syphilitic mucosal ulceration
- Syphilitic oral snail track ulcer
- Syphilitic punched out ulcer
- Syphilitic skin disorder
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Syphilitic leukoderma
- Syphilitic mucous patch
Type 1 Excludes
- late syphilitic leukoderma A52.79
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Atrophoderma, atrophodermia (of) - L90.9
- syphilitic - A51.39
- macular (dermatological) - L90.8
- syphilitic, skin - A51.39
- Leukoderma, leukodermia NEC - L81.5
- syphilitic - A51.39
- Mucous - See Also: condition;
- patches (syphilitic) - A51.39
- Patches
- mucous (syphilitic) - A51.39
- Rupia (syphilitic) - A51.39
- Syphilid - A51.39
- Syphilis, syphilitic (acquired) - A53.9
- anus (late) - A52.74
- secondary - A51.39
- atrophoderma maculatum - A51.39
- skin - A51.39
- symptomatic - A51.9
- secondary - See Also: Syphilis, secondary; - A51.39
- ulcer - A51.39
- leukoderma - A51.39
- lip - A51.39
- macular atrophy of skin - A51.39
- mouth (secondary) - A51.39
- mucocutaneous (secondary) - A51.39
- mucous
- membrane (secondary) - A51.39
- patches - A51.39
- pharynx (late) - A52.73
- secondary - A51.39
- skin (with ulceration) (early) (secondary) - A51.39
- tonsil (lingual) (late) - A52.73
- secondary - A51.39
- ulcer (any site) (early) (secondary) - A51.39
- secondary - A51.39
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Atrophoderma, atrophodermia(of)
- maculatum
- syphilitic
- Atrophy, atrophic(of)
- macular (dermatological)
- syphilitic, skin
- Leukoderma, leukodermia NEC
- syphilitic
- Mucous
- patches (syphilitic)
- Patches
- mucous (syphilitic)
- Rupia(syphilitic)
- Syphilid
- Syphilis, syphilitic(acquired)
- anus (late)
- secondary
- Syphilis, syphilitic(acquired)
- atrophoderma maculatum
- Syphilis, syphilitic(acquired)
- early
- skin
- Syphilis, syphilitic(acquired)
- early
- symptomatic
- secondary
- Syphilis, syphilitic(acquired)
- early
- ulcer
- Syphilis, syphilitic(acquired)
- leukoderma
- Syphilis, syphilitic(acquired)
- lip
- Syphilis, syphilitic(acquired)
- macular atrophy of skin
- Syphilis, syphilitic(acquired)
- mouth (secondary)
- Syphilis, syphilitic(acquired)
- mucocutaneous (secondary)
- Syphilis, syphilitic(acquired)
- mucous
- membrane (secondary)
- Syphilis, syphilitic(acquired)
- mucous
- patches
- Syphilis, syphilitic(acquired)
- pharynx (late)
- secondary
- Syphilis, syphilitic(acquired)
- secondary (and primary)
- anus
- Syphilis, syphilitic(acquired)
- secondary (and primary)
- mouth
- Syphilis, syphilitic(acquired)
- secondary (and primary)
- mucous membranes
- Syphilis, syphilitic(acquired)
- secondary (and primary)
- pharynx
- Syphilis, syphilitic(acquired)
- secondary (and primary)
- skin
- Syphilis, syphilitic(acquired)
- secondary (and primary)
- tonsil
- Syphilis, syphilitic(acquired)
- secondary (and primary)
- ulcer
- Syphilis, syphilitic(acquired)
- secondary (and primary)
- vulva
- Syphilis, syphilitic(acquired)
- skin (with ulceration) (early) (secondary)
- Syphilis, syphilitic(acquired)
- tonsil (lingual) (late)
- secondary
- Syphilis, syphilitic(acquired)
- ulcer (any site) (early) (secondary)
- Syphilis, syphilitic(acquired)
- vulva
- secondary
- Ulcer, ulcerated, ulcerating, ulceration, ulcerative
- syphilitic (any site) (early) (secondary)
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Skin Infections
Your skin is your body's largest organ. It has many different functions, including covering and protecting your body. It helps keep germs out. But sometimes the germs can cause a skin infection. It often happens when the germs enter your body through a break, cut, or wound on your skin.
The full article covers:
- What are skin infections?
- What causes skin infections?
- Who is more likely to get a skin infection?
- What are the symptoms of skin infections?
- How are skin infections diagnosed?
- How are skin infections treated?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert A51.39 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About A51.39Overview
Is A51.39 (Secondary syphilis of skin and mucous membranes) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other secondary syphilis of skin on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does A51.39 group to?
When other secondary syphilis of skin is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of A51.39?
Under the General Equivalence Mappings, other secondary syphilis of skin converts to ICD-9-CM 091.3 (secondary syph skin). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
