How to Interpret and Managing Purified Protein Derivative Skin Tests

In Episode 65 of Med School Question of the Week for USMLE, Alisa Khomutova, MedSchoolCoach expert tutor, answers this medical school question: A 24-year-old man comes to the physician to establish routine care. He feels well. He has no PMH. He immigrated from Nepal 3 weeks ago. He lives in a shelter. He has smoked one pack of cigarettes daily for the past 6 years. He has not received any childhood vaccinations. He appears healthy. Vitals and physical exam wnl. A purified protein derivative (PPD) skin test is performed. Three days later, an induration of 13 mm is noted. Which of the following is the most appropriate initial step in the management of this patient?

• Immediate Respiratory Isolation
• Collect sputum for culture
• Collect sputum for PCR
• Interferon Gamma release Assay
• Obtain a chest xray
• Isoniazid for 9 months (with B6)
• RIPE therapy
• Reassurance