From scrophula to mycobacterial lymphadenitis

In the 19th century it was widely believed that both tuberculosis and cervical lymph node swelling, known as scrophula, affected individuals predisposed to an inherited diathetic constitution. In 1882 Robert Koch proved that human tuberculosis and scrophulous lesions were caused by the bacillus Mycobacterium tuberculosis. In the early twentieth century it was stated that Mycobacterium bovis, the bacillus of cattle tuberculosis, could also cause cervical lymphoadenitis in humans, especially in children, by the intake of milk from sick cows. The incidence of this condition decreased after the infection was controlled in cattle and pasteurization of the milk was introduced. A type of granulomatous necrotizing and suppurative cervico-facial lymphadenitis associated to non-tuberculous mycobacteria was described in 1956. It mainly affects children younger than 5 years old, particularly those born in countries with non-endemic tuberculosis. Tuberculous cervical lymphadenitis is prevalent in young adults from tuberculosis-endemic countries and in HIV-infected subjects. Infectious etiology displaced the importance of a personal disposition in the development of scrophula. Nevertheless, mutations that confer susceptibility to mycobacterial infection are currently investigated.