Discussion:
The diagnosis of brucellosis with a wide range of nonspecific clinical presentations may last for months, as it occurred in our case, in which the specific therapy was started for him after several months of being symptomatic. The extended disease and inappropriate treatment may lead to even more severe consequences and some of the body system impairment.5 On the other hand, responding slowly to the specific treatment is one of the characteristics of brucellosis, and this feature led to pulmonary manifestations in our case while he had been treated with effective medications for a week.
In addition to the common clinical findings in brucellosis, including fever, headache, malaise and weakness, myalgia, arthralgia, backache, and anorexia, some organs of the body may be affected like gastrointestinal, respiratory, cardiovascular, hematopoietic, and nervous systems.6
Andriopoulos et al. in 2007 investigated the presentation, diagnosis, and treatment of 144 cases of acute brucellosis. According to the data, no one exerted respiratory impairment features; however, osteoarticular, hematologic, or gastrointestinal complications were confirmed in many cases.7
The incidence of respiratory complications of brucellosis has been reported lower than 1 to 5%. The exact pathophysiology of this complication is not defined well. The most reported symptoms are fever, cough, dyspnea, sputum production, hemoptysis, and lymphadenopathy; and the most radiographic findings are interstitial pattern, lobar pneumonia, and pleural effusion.8
Studies showed that timely diagnosis and appropriate treatment result in a good prognosis. Hakan Erdem et al. in the largest series of pulmonary brucellosis in 2014 showed that the most symptoms of the patients were fatigue (87.2%), cough (85.7%), sweating (79.6%), lack of appetite (74.4%), and arthralgia (68.4%); while, our patient referred with chest pain, arthralgia, and low-grade fever. In that research, the most forms of pulmonary involvement were pneumonia, pleural effusion, bronchitis, nodular lung lesions, pulmonary embolism, ARDS, and surprisingly no pleurisy.9
To the best of our knowledge, there are three published case reports of brucella pleurisy, which all were completely recovered after treatment with rifampin plus doxycycline for a total of 8 to 12 weeks. There were also no radiological findings or relapses on their follow-up.10-13 The same was happened to our case, except for the selected regimen according to the patient’s intolerance, which was consisted of ofloxacin instead of doxycycline.
Brucellosis and tuberculosis (TB) often are endemic in some regions simultaneously. Since they are completely different in treatment strategies, it is important to differentiate the respiratory involvement of brucellosis from TB infection.14 Of course, the presence of arthralgia along with the history of unpasteurized dairy products consumption can be considered to the detriment of TB diagnosis. Since Iran is an endemic region for TB, TB infection was ruled out for our patient with a negative MTB-PCR test. It should be noted that the pleural fluid adenosine deaminase (ADA) levels elevate in TB, and measuring ADA alone could not help to confirm brucellosis.10