Elbow mycobacterium tuberculosis in america.

Sir

Less than 1% of tuberculosis (TB) cases are specific to the elbow.[12] Symptoms often develop insidiously, and in the absence of pulmonary involvement, TB is typically excluded from the differential diagnosis.

A 69-year-old man, originally from Pakistan, presented with elbow swelling, pain, and decreased range of motion. His medical history included dengue, entamoeba histolytica, and gout. He reported recent unexplained changes in weight, weakness and fatigue, loss of appetite, changes in skin, blurred vision, coughing, smoking, abdominal pain, frequent diarrhea, and constipation. Vital signs were within normal limits. There was no skin breakdown or lesions. The elbow demonstrated diffuse swelling, but no redness. Radiographs revealed mild osteoarthritis, but no acute fractures.

The elbow joint was aspirated without complication. The patient was negative for rheumatoid factor and lyme disease. The C-reactive protein was within normal limits, and the sedimentation rate was 29 mm/h.

Despite no trauma, 6 months later, the patient reported increased swelling, pain, and decreased range of motion. The elbow demonstrated moderate effusion and some warmth, but no ecchymosis. Radiographs showed increased erosion of the capitellum and radial head, but no acute fractures or subluxation.

The joint was aspirated without complication. No aerobic growth or crystals were seen. Given the worsening symptoms, the patient was admitted for incision and drainage of the right elbow and olecranon bursa. Tissue, bone, and fluid specimens were obtained.

Pulmonary TB was ruled out. Acid-fast Bacilli (AFB) cultures were obtained for all surgical specimens. The primary culture media included a Remel Mitchison 7H11 Selective Agar Slant (Thermo Scientific™ Remel™, Waltham, MA) and a VersaTREK® Myco liquid medium (TREK Diagnostic Systems, Oakwood Village, OH). Growth was present on the slant and in the liquid medium. Both the agar slant and the liquid medium were Kinyoun positive.

Twelve days after the specimen was submitted; Mycobacterium probes were tested on the culture. The Mycobacterium TB (MTB) probe was positive, and the Mycobacterium avium probe was negative.

The mycobacteria were sub-cultured to Lowenstein-Jensen agar slants (Thermo Scientific™ Remel™, Waltham, MA) and Middlebrook 7H10 agar plates (Thermo Scientific™ Remel™, Waltham, MA). A Lowenstein-Jensen slant was sent to the Pennsylvania Department of Health Bureau of Laboratories for further identification and susceptibility testing. By high-performance liquid chromatography, the isolate was identified as MTB complex. The MTB isolate was susceptible to all drugs tested (isoniazid [0.1 and 0.4 μg/mL], ethambutol [5.0 μg/mL], rifampin [1.0 μg/mL], and pyrazinamide [100 μg/mL]).

Although TB control has dramatically improved, the proportion of extra-pulmonary cases in the United States has progressively increased from 16% in 1993 to 21% in 2012.[3] The female gender, nonwhite race and/or ethnicity, foreign birth, and positive HIV status have emerged as risk factors.[45]

In the present report, the patient presented with elbow pain, soft tissue swelling, and reduced function. He was of nonwhite race, born outside of the United States, and was positive for recent weight loss. The authors advocate the consideration of AFB cultures in cases of monoarticular chronic inflammation to facilitate prompt diagnosis and limit morbidity and mortality.