Tuberculosis paradoxical reaction.

T is endemic in this part of the world. We frequently encounter patients with both pulmonary and extrapulmonary tuberculosis regardless of whether they are infected with human immunodeficiency virus (HIV) or not. It is not uncommon for physicians to see clinical or radiological, or both, worsening of the disease while their patient is on anti-tuberculous treatment, the so-called paradoxical reaction. We briefly describe an interesting case of paradoxical reaction and address how to approach such a clinical situation. An 18-year-old Saudi female presented to us with complaints of intermittent right flank swelling of onemonth duration. The swelling progressively increased in size and would appear on standing and disappear on lying down. There was no associated abdominal pain or other gastrointestinal or urinary symptoms. The patient denied history of fever, weight loss, or backache. She was diagnosed to have multifocal skeletal tuberculosis involving the hyoid bone, right mastoid bone, right occipital bone, and first 2 cervical vertebrae 5 months before presentation. At that time, she presented to her local physician with fever, weight loss, hearing loss, and purulent discharge from the right ear, and swelling of the right side of the neck overlying the hyoid bone. A biopsy from the hyoid bone revealed caseating granulomas on histopathological examination. Smears for acid-fast bacilli, mycobacterial DNA probe and cultures of the biopsy tissue were not obtained at that time. Computed tomogram scan (CT scan) of the head and neck was performed then and revealed lytic lesions in the above mentioned bones. Since tuberculosis is endemic in the area, it was presumed that the patient has multifocal skeletal tuberculosis. The patient was treated with 2 months isoniazid, rifampin, ethambutol, and pyrazinamide, and was then continued on maintenance antituberculous therapy (isoniazid and rifampin). In the fourth month of treatment, the patient presented to us with the complaint of swelling in the right flank. The patient tolerated the medication well and was compliant with her treatment and follow up visits. Shortly after starting therapy, her fever, and ear discharge resolved and her weight and feeling of wellbeing improved significantly. On examination, the patient was afebrile and looked healthy. Abdominal examination revealed a nontender and soft fluctuant swelling in the right flank, which became prominent with the standing position. There were no overlying skin changes. Examination of the spine was normal. The rest of the physical examination was unremarkable. Her initial laboratory work up including blood counts, sedimentation rate, renal function, and liver function tests were within normal range of reference laboratory values. The x-ray of the chest was normal. Purified protein derivative (PPD) test was positive (>10 mm). Contrast CT scan of the abdomen revealed bilateral psoas abscesses (Figure 1a & 1b). The right one was bigger and extending down into the abdominal wall and pelvis. No previous images of the abdomen or dorsolumbar spine were available. The patient had no evidence of malabsorption and compliance to medication was assured. A CT guided aspiration of the right psoas abscess described on CT scan of the abdomen was performed for further evaluation. Gram staining of the aspirate was negative. Acid fast staining and mycobacterium tuberculosis DNA probe (MTB probe) were positive. We then added ethambutol, pyrazinamide, amikacin, and moxifloxacin to her current antituberculous regimen to cover for a possible Clinical Note