A 34-year-old man with Crohn disease presents to the emergency department with a 3-week history of fever, productive cough, and progressive dyspnea. He has been on infliximab monotherapy for 8 months for refractory colonic disease. Vital signs include temperature 39.1°C, heart rate 108 bpm, respiratory rate 24/min, and oxygen saturation 89% on room air. Physical examination reveals diminished breath sounds at both lung bases. Chest X-ray shows bilateral hilar lymphadenopathy with mediastinal widening and right middle lobe infiltrate. Purified protein derivative (PPD) skin test is negative (5 mm induration). Sputum samples are sent for microscopy and culture. Which of the following is the most likely explanation for this patient's pulmonary presentation?
- A)Disseminated histoplasmosis
- B)Acute exacerbation of Crohn disease with pulmonary involvement
- C)Tuberculosis despite negative PPD skin testGABARITO
- D)Drug-induced systemic lupus erythematosus from TNF-α inhibitor
- E)Mycobacterium avium complex infection
Explicação
Tuberculosis is the most likely diagnosis. TNF-α inhibitors (infliximab) profoundly increase TB risk by impairing cell-mediated immunity, particularly Th1 responses critical for mycobacterial containment. A negative PPD does not exclude active TB in immunosupp... Ver explicação completa e trilha adaptativa →