Tuberculosis is still one of the most prevalent infectious diseases in developing countries like Bhutan. As per the world health organization (WHO) the estimated incidence of TB cases in Bhutan in 2019 was 1,300 cases. Caused by Mycobacterium tuberculosis, it affects the pulmonary system which can be fatal if not treated on time. Although tuberculosis can affect almost every organ in our body, lungs are the most commonly affected organ. A rare site getting affected, ulcers in the oral cavity are generally not worked up to rule out tuberculosis often causing missed diagnosis and treatment delay.

We present a case of a middle-aged woman who complained of a non-healing ulcer at lateral border of tongue for 6 months’ duration. Its treatment failed to show improvement and, therefore, reconsidering its diagnosis was warranted. Histopathological findings revealed presence of langhans giant cells that confirmed tuberculosis. The clinical presentations, differential diagnosis and management of such oral manifestations are discussed subsequently.

Keywords: Oral tuberculosis; Tongue; Ulcer

Tuberculosis (TB) is an airborne infectious disease transmitted by inhaled aerosolized droplets from patients with active infection. Prevalently affecting middle aged males, it can affect any person of all age groups. TB can affect any organs of the body, the lung being the most common site of infection [1]. Although the risk of transmission of tuberculosis in dental setting is low with only 5% of total TB cases may present with oral manifestations [2]. Oral lesions and ulcerations can be the first manifestation in oral cavity even though if it is rare. A non-healing ulcer, papillomas with circumferential soft tissue induration or inflamed patches may be seen. The histopathological findings vary from numerous necrotic tissues, macrophages, epithelioid cells and multinucleated langhans giant cells are the main morphologic characteristic features of TB [3]. Early diagnosis of oral lesions caused by TB can be correctly diagnosed by dental professionals and start treatment without delay.

A 46 years old woman presented with the complaint of non- healing ulcer on the left lateral border of the tongue for 6 months gradually increasing in size. The painless ulcer had developed without any history of trauma. However, she complained of discomfort and pricking sensation at the site of ulceration. Patient had no history of alcohol and tobacco consumption. She had significantly lost weight unintentionally without apparent changes in her appetite.

Oral TB is categorized into primary and secondary. Primary oral TB is infrequent and usually seen in children and secondary TB is commonly seen in adults in association with lung involvement. Apart from the tongue, palate, lips, buccal mucosa, gingiva and oral floor can also be affected. The lesion may present as ulcer, nodules, tuberculomas and granulomas.

Physical examination revealed no remarkable external facial changes as shown in [Figure 1].

Figure 1: Patients Facial Profile (Frontal View).

Intraoral examination, we came across punched-out ulcer measuring approximately 10 cm in diameter at the left lateral border of the tongue as shown in [Figure 2]. The ulcer exhibit indurated base, undermined edge with tender margins. Patient did not have any predisposing factors such as sharp teeth, root stumps, no history of traumatic bite or injury neither any chemical burns which could have led to ulceration. Usually tuberculosis ulcers of tongue involve the tip, lateral borders, dorsum, the midline and base of the tongue [4].

Figure 2: Ulcer on Lateral Border of the Tongue.

The laboratory examinations showed that complete blood count (CBC) was within normal limits, erythrocyte sedimentation rate (ESR) was minimally accelerated, chest x ray was normal, venereal disease research laboratory (VDRL) and T. pallidum hemagglutination assay (TPHA) were non-reactive, gene X-pert was negative,and blood sugar was within normal limits. During histopathological examination, incisional biopsy was performed under local anesthesia (2% lidocaine with epinephrine 1: 100,000). The histological findings revealed numerous necrotic tissues, langhans giant cells and inflamed granulation tissue with epithelioid cells which confirmed TB ulcer. Other immune-compromised conditions or neoplastic disorders were ruled out. Traumatic ulcers, aphthous ulcer, tongue cancer, chancre granuloma are some of the differential diagnoses [5].

Once tuberculosis was confirmed, antituberculosis treatment (ATT) was administered. The treatment of oral tuberculosis lesions is the same as the systemic tuberculosis, which involves a combination of four drugs isoniazid, rifampicin, pyrazinamide and ethambutol administered daily for the first two months, followed by an additional four months with only two drugs (isoniazid and rifampicin). A course of antibiotics and vitamin supplements were also given after discussing with medical specialist. Meanwhile, patient was advised to maintain good oral hygiene and was given oral topical analgesic ointment in case of pain. However, through teeth grinding was done for any chances of irritation to the tongue.

Table 1 depicts the TB infection control based on three levels of control to be followed by the dental professionals to reduce the risk of exposure to potentially infectious persons.

Table 1: Tuberculosis Precautions for Outpatient Dental Settings.

Worldwide tuberculosis is one of the leading causes of death beside HIV/AIDS which is slowly decreasing due to early diagnosis and proper medication [6]. TB is most susceptible in the pulmonary system and usually does not occur in other parts of the body. However, in rare instances, progressive pulmonary TB spreads by self-inoculation via infected sputum, blood, or lymphatic system to cause secondary lesions of TB at organs other than the lung. TB can affect the head and neck regions, which mostly involves the oral cavity, oral TB is an uncommon disease with an incidence of 0.5-1.5% [7]. Systemic or Pulmonary tuberculosis was ruled out. There were no involvement os gingiva and buccal mucosa. A solitary ulcer on the tongue was the only ulcer present in our present. In the oral cavity, TB lesions mostly found on the dorsum of the tongue and usually lesions may either be primary or secondary (most common) [8]. Generally, oral TB lesions appears as ulcer, nodules or vesicle, fissures, granulomas or tuberculmas lesions of the mucosa. Usually the typical TB ulcer are non-healing and superficial in appearances characterized by undermined edges, ragged, indurated and often painful [9]. If oral TB lesions are associated with bones involving the maxilla or mandible, may be due to deep extension of gingival lesions or infected post extraction sockets which may result in tuberculous osteomyelitis.

 TB oral lesions does not exhibit precise clinical manifestations and are often overlooked in differential diagnosis by the health caregivers. Similarly, the present case was diagnosed as aphthous ulcer or traumatic ulcer at first, because of prolonged ulcerations. Despite proper medications and with no history of trauma it was further examined to rule out TB. Considering other systemic illnesses like syphilis and crohn’s disease, radiographic and histopathologic studies must be regarded to provide the definite diagnosis.

As dental personnel are the first health care professionals at constant risk of getting exposed to TB by means of splatter, aerosols, or infected body fluids, they are the ones who frequently encounter various oral lesions. Therefore, it is crucial that dental professionals recognize the various oral manifestations of oral TB to prevent late initiation of treatment and poor prognosis. Considering this, the council recommends to include such topics in the curriculum during the study period at the Faculty of Nursing and Public Health, Khesar Gyelpo University of Medical Sciences of Bhutan. Further, it emphasizes to have dental subjects for all the paramedics so that they not only learn but not miss the cases during their practice in future. After proper diagnosis the patient was treated with 6 months long Anti-Tubercular therapy (ATT). The patient was followed at 6 months and 12 months. The patient improved well with no relapse of the disease.

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Corresponding author: Gyan Prasad Bajgai, Department of Dentistry, Jigme Dorji Wangchuck National Referral Hospital, Bhutan