Review Question - QID 221102

This patient who presents with hemoptysis, weight loss, and night sweats most likely has a Mycobacterium tuberculosis infection that was treated with combination therapy that includes pyrazinamide. Gout flare is a known side effect of pyrazinamide treatment.

Patients with active pulmonary tuberculosis present with hemoptysis, weight loss, and night sweats among many other symptoms. The diagnosis can be made with a chest radiograph in a patient with a positive tuberculin skin test or interferon gamma release assay. Acid-fast bacilli would be detected on sputum cultures. Active infection with Mycobacterium tuberculosis is typically treated with combination therapy with rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE). Pyrazinamide and ethambutol are discontinued after 2 months and rifampin and isoniazid are continued for 4 more months. Pyrazinamide has an unknown mechanism of action but appears to involve the activity of the host phagolysosomes. Side effects of this medication include hepatotoxicity and hyperuricemia. This latter effect can result in a gout flare.

Scott reviews the evidence regarding the development of drug-induced gout. He discusses how multiple medications can be responsible for the elevation of uric acid levels, leading to gout. They recommend considering this mechanism if a patient is on pyrazinamide.

Figure/Illustration A is a clinical photograph that demonstrates a swollen, erythematous first metatarsophalangeal joint (black circle). This appearance is classically seen in patients with gout.

Incorrect Answers:
Answer 1: Autoimmune phenomenon is responsible for systemic lupus erythematosus and other membranous diseases. Drug-induced lupus can be caused by isoniazid therapy; however, this condition would also present with other symptoms such as a macular rash and glomerulonephritis.

Answer 2: Dissemination of disease, referring to miliary tuberculosis, can involve the bones and cause musculoskeletal pain. Disseminated tuberculosis would present as a worsening of symptoms, including increased cough and hemoptysis. This patient presents at follow-up with an improvement of his other symptoms, so he is not likely to have an isolated progression of bony pain.

Answer 4: Oncologic processes such as leukemia can also present with gout after treatment with lytic therapy. These conditions may also have fever and weight loss as side effects but are unlikely to involve hemoptysis.

Answer 5: Trauma can lead to inflammation of the great toe due to a fracture or ligamentous injury. The appearance of this toe is more consistent with gout, given the isolated erythema and swelling of the metatarsophalangeal joint.

Bullet Summary:
Gout flare is a known side effect of pyrazinamide treatment.