A50.55

HCC Category Mapping

What This Code Means

This is a joint disease that develops in children born with syphilis, occurring years after birth as a late complication of the infection passed from mother to child. The condition causes inflammation and damage to the joints, typically affecting the knees and other large joints.

Coding Tips

• •This code requires documentation confirming late congenital syphilis with arthropathy involvement; verify the patient has a history of congenital syphilis and current joint manifestations
• •Do not use this code for acquired syphilis or early congenital syphilis; ensure the clinical record specifies this is a late manifestation occurring after age 2 years

Clinical Significance

Late congenital syphilitic arthropathy represents a chronic manifestation of untreated congenital syphilis that develops years after birth, indicating ongoing infectious disease burden requiring long-term management. This condition reflects both the severity of the original congenital infection and the complexity of managing its late sequelae.

Documentation Requirements

• ✓Confirmed history of congenital syphilis (maternal transmission documented)
• ✓Onset after age 2 years (distinguishing late from early congenital syphilis)
• ✓Specific joint(s) involved with clinical findings (swelling, effusion, limitation of motion)
• ✓Serological confirmation (positive treponemal tests such as FTA-ABS)
• ✓Current treatment plan and disease activity status

Commonly Confused Codes