Abstract
According to Japan’s tuberculosis statistics, in 2014 the incidence rate of tuberculosis (TB) per 100,000 people was 15.4, and the death rate from TB per 100,000 people was 1.7. Although the incidence rate of TB in Japan has decreased year-on-year, from 18.2 in 2010 to 17.7 in 2011, 16.7 in 2012, and 16.1 in 2013, the rate still remains high compared to that in other developed countries, and Japan is ranked as an intermediate-burden country. There are very large regional differences in the incidence rate of TB, with high incidence rates in urban areas such as Osaka (36.8), Nagoya (23.2), and Tokyo (21.2); in contrast, the lowest incidence rate is 8.1 in Nagano. Additionally, the proportion of new TB patients amongst the elderly population is still high. Although pulmonary TB (PTB) is the most common type of TB, extrapulmonary manifestations are also seen. Otolaryngologists encounter extrapulmonary TB (EPTB) most commonly as cervical tuberculous lymphadenitis. The 47 cases of head and neck TB that we have seen in the past 10 years consist of 30 cases of cervical lymph node TB (63.8%), 12 of laryngeal TB (25.5%), 3 of parotid gland TB, and 2 of middle ear TB. Because TB can manifest itself in many different ways, otolaryngologists who deal with upper respiratory diseases should always be aware of the possibility of TB in clinical practice. The concurrence rate of active PTB in patients with cervical tuberculous lymphadenitis is not high, while laryngeal TB, although a less common form of head and neck TB, frequently occurs in conjunction with active PTB. Head and neck cancer is one of the high risk conditions for the development of TB, and otolaryngologists should be aware of the risk of secondary TB development in patients with head and neck cancer.
