ممرضة عملت فحص السل الجلدي (PPD). متى يُقرأ وما الإيجابي لعاملة صحية؟

A nurse has a tuberculin skin test. When is it read and what is positive for a healthcare worker?

1. At 24 hours; 5 mm of redness
2. At 48–72 hours; induration of 10 mm or more
3. At 2–4 hours; any redness at the site
4. After a week; any itching at the site

Answer: B) At 48–72 hours; induration of 10 mm or more. It is read at 48–72 hours by measuring induration, not redness; for healthcare workers 10 mm or more is positive.