What is the ICD-10 code for a positive PPD (Purified Protein Derivative) and what is the recommended imaging study, such as a chest X-ray (CXR), for a patient with a positive result?

ICD-10 Code and Chest X-Ray for Positive PPD

For a positive PPD test, use ICD-10 code R76.11 (Nonspecific reaction to tuberculin skin test without active tuberculosis), and a chest X-ray is mandatory to exclude active tuberculosis before any treatment decisions are made.

ICD-10 Coding

• R76.11 is the appropriate code for a positive PPD/tuberculin skin test result in an asymptomatic patient without evidence of active disease 1
• If chest X-ray reveals findings consistent with old healed TB, use code for latent tuberculosis infection after active disease is excluded 2
• If active TB is confirmed, code as A15.0 (respiratory tuberculosis) or appropriate subcategory based on site 1

Mandatory Chest X-Ray Evaluation

All individuals with newly recognized positive PPD test results must undergo chest radiography to exclude active tuberculosis before any treatment decisions. 1, 3

Specific radiographic findings to evaluate:

• Upper lobe infiltration with or without cavitation - strongly suggests active TB 2
• Apical or subapical posterior upper lobe nodular infiltrates - classic pattern for active disease 2
• Superior segment lower lobe involvement - another typical location 2
• Hilar or mediastinal lymphadenopathy - particularly in immunocompromised patients 2
• Apical fibronodular infiltrations with volume loss - suggests prior healed TB 2
• Pleural effusion or thickening - may indicate active or prior disease 2

Critical clinical algorithm:

1. Order chest X-ray immediately after positive PPD 1, 3
2. If chest X-ray shows any abnormality OR patient has any TB symptoms (cough, fever, night sweats, weight loss, hemoptysis): collect sputum for AFB smear and culture x3 specimens on different days 2
3. If chest X-ray is normal AND patient is asymptomatic: proceed with treatment for latent TB infection 1, 3
4. If chest X-ray shows old healed TB findings (apical fibronodular changes): still obtain sputum cultures to definitively exclude active disease before treating as latent TB 2

Important Caveats

• Immunocompromised patients (especially HIV with CD4 <100) may have atypical or even normal chest X-rays despite active TB - consider CT chest if clinical suspicion remains high 2
• Recent research shows very low yield (1% abnormal findings) of chest X-rays in asymptomatic children with positive PPD in low-prevalence US settings, but guidelines still mandate the study 4
• Do not skip chest X-ray even in asymptomatic patients - approximately 2.5 times higher risk of developing active TB exists in those with radiographic abnormalities consistent with prior TB 2
• BCG vaccination history does not change management - a PPD ≥10mm in adults from high-prevalence countries who received BCG as children should be attributed to M. tuberculosis infection, not vaccine 2

Documentation Requirements

Document the following for proper coding and clinical management:

• PPD induration size in millimeters 1, 3
• Risk factors present (HIV, immunosuppression, close contact, healthcare worker, immigrant from endemic area) 1, 5
• Chest X-ray results with specific description of any abnormalities 1, 3
• Presence or absence of TB symptoms (cough >3 weeks, hemoptysis, fever, night sweats, weight loss) 1, 3