The impact of tuberculosis (TB) falls mainly on developing nations. In most industrialized countries, the annual numbers of cases and deaths caused by TB have steadily declined over the past century up to the mid-1980s . Since then, an increasing number of TB cases in immigrants has reversed this downward trend in several countries . Despite increased immigration over the last years, the number of reported TB cases in Switzerland has stayed unchanged . The cases in persons with Swiss nationality declined continuously and was 28% in 2009. The median age of patients suffering from TB in Switzerland is 65 years in patients with Swiss nationality and 31 years in foreigners .

TB is an infectious bacterial disease. The infection is most frequently caused by Mycobacterium tuberculosis and less frequently by Mycobacterium bovis . It is transmitted from person to person through the air via droplets. The primary infection usually occurs in the lungs. From there it spreads to other organs and tissues. It may also occur in other parts of the body, including bones and major joints. The prevalence of extrapulmonary TB has increased in the last couple of years, especially related to the AIDS epidemic. Head and neck tuberculosis forms nearly 10% of all extrapulmonary manifestations of the disease . TB infections of the facial bones have been described . There are only a few reports of TB infections of the temporomandibular joint (TMJ) .

TB of the TMJ is easily misdiagnosed as arthritis or cancer. The aim of this publication is to point out the importance of TB as a differential diagnosis in TMJ diseases. The correct diagnosis is necessary in order to start the appropriate therapy. If the diagnosis is missed and the appropriate treatment is delayed, the degree of joint destruction and osteoarthritic-like changes can be severe .

Case report

A 22-year-old African woman was referred to the authors’ department. She had resided in Switzerland for 4 years having migrated from Ethiopia. Six months before presenting she was seen by her family doctor with pain in the left TMJ. She was treated with non-steroidal anti-inflammatory drugs which gave her symptomatic relief. Three months later she experienced a progressive preauricular swelling. At that stage the family doctor referred her to a dentist, who took a panoramic radiograph that revealed bone resorption in the area of the left condyle. A magnetic resonance imaging (MRI) examination showed an expansive lesion with destruction of the left condyle and the condylar fossa, without alteration of the disc. The patient was referred with these findings. Initial review showed a painful preauricular swelling with painful trismus ( Fig. 1 ). The patient was otherwise well. There were no known drug allergies or regular medication intake. On examination she had a large, soft preauricular swelling on the left side and reduced, painful mouth opening. Her vital signs were normal and there was no lymphadenitis. A computed tomography (CT) of the head and neck showed a preauricular subcutaneous mass of 2.5 × 2.5 cm, adjacent to the parotid gland, with a liquid-like centre and resorption of the dorsal part of the condylar head ( Fig. 2 ).

(A) Patient before treatment, demonstrating preauricular swelling; (B) lateral view.

(A) Initial CT scan: partial destruction of the left condyle (arrow); (B) preauricular soft tissue mass on the left side (arrow).

A fine needle aspiration was performed which showed granulomatous inflammation. No neoplastic cells were found. Eight days later a biopsy and a swab were carried out under local anaesthesia. Following this intervention, antimicrobial therapy with amoxicillin and clavulanic acid (2 g/day, orally) was started. The assessment of the swab (auramin staining and polymerase chain reaction) revealed an infection with M. tuberculosis . The biopsy showed an unspecific necrotising granulomatous inflammation. With this finding the patient was referred to the Department of Infectious Diseases where she was examined thoroughly. Pulmonary infection was excluded by three negative sputa and a normal chest X-ray. No evidence for other focuses of the TB (spine X-ray, ultrasonic of abdomen) was found and an HIV test was negative. An infection of the middle ear was excluded by CT and MRI. The initial chemotherapy consisted of a combination of four different antibiotics (rifampicin, isoniazid, pyrazinamide and ethambutol). Two months after initiation of the treatment the resistance test showed sensitivity for all antibiotics administered. The number of antibiotics was then reduced to two (isoniazid and rifampicin). The treatment was completed successfully after 9 months. A CT scan 2 months after the end of treatment showed disappearance of the soft tissue mass and partial regeneration of the condylar head ( Fig. 3 ). There was no more pain or swelling and the scar was aesthetically satisfying ( Fig. 4 ). The patient was considered to be healed and discharged from further follow-up.

(A) CT scan 2 months after completion of treatment: partial regeneration of the left condyle with remaining slight depression of the posterior surface (arrow); (B) complete regression of soft tissue swelling.

(A) Patient 2 months after completion of treatment, front view: the swelling has completely subsided; (B) preauricular region with acceptable cosmetic result.