Tuberculous lymphadenitis

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Tuberculous lymphadenitis

AuthorSection Editor

http://www.uptodate.com/contents/tuberculous-lymphadenitis?topicKey...Deputy Editor

Denis Spelman, MBBS, FRACP,C Fordham von Reyn, MDElinor L Baron, MD, DTMH

FRCPA, MPH

Disclosures

All topics are updated as new evidence becomes available and our peer review process is complete. Literature review current through: Feb 2014. | This topic last updated: Jul 3, 2013.

INTRODUCTION Tuberculous lymphadenitis is among the most frequent presentations of extrapulmonary

tuberculosis (TB). Tuberculous lymphadenitis in the cervical region is known as scrofula [1]. This syndrome can also be caused by nontuberculous mycobacteria.

TB is responsible for up to 43 percent of peripheral lymphadenopathy in the developing world [2]. In rural India, the prevalence of tuberculous lymphadenitis in children up to 14 years of age is approximately 4.4 cases per 1000 [3]. In the United States, about 20 percent of patients with TB have extrapulmonary disease, and lymphadenitis is a presenting symptom in about 30 to 40 percent of cases [4-6]. (See "Evaluation of peripheral lymphadenopathy in adults".)

The human immunodeficiency virus (HIV) epidemic has been associated with an increase in the total incidence of TB and an increased proportion of miliary, disseminated, and extrapulmonary TB cases including lymphadenitis [7]. (See "Epidemiology of tuberculosis" and "Epidemiology and pathology of extrapulmonary and miliary tuberculosis".)

Issues related to tuberculous lymphadenitis will be reviewed here. Other issues related to tuberculosis are discussed separately (see related topics).

PATHOGENESIS Isolated peripheral tuberculous lymphadenopathy is usually due to reactivation of disease at a site seeded hematogenously during primary TB infection, perhaps years earlier [8].

It has been postulated that cervical TB lymphadenitis occurs as a result of TB infection involving the tonsils,

adenoids and Waldeyer's ring, leading to cervical lymphadenopathy [2]. Abdominal TB lymphadenopathy may occur via ingestion of sputum or milk infected with Mycobacterium tuberculosis or M. bovis [9]. (See "Microbiology and pathogenesis of tuberculosis" and "Mycobacterium bovis".)

Though most cases of TB lymphadenitis occur in the setting of reactivation of latent infection, miliary dissemination with prominent lymph node involvement in the setting of primary infection can also occur [7,10,11].

EPIDEMIOLOGY The epidemiology of TB lymphadenitis varies between developed and developing countries.

In developed countries, most cases of TB lymphadenitis occur among adult immigrants from TB endemic countries [12-14]. This was illustrated by case series of TB lymphadenitis in France and Germany in which about 70 percent of cases occurred in immigrants; in the German study, two-thirds of patients had immigrated >3 years prior to diagnosis [12,13]. In the United States, the rate of TB lymphadenitis is higher among Asian Pacific Islanders and in females [2,5,15]. Rarely, TB lymphadenitis can also occur in travelers to endemic areas [16,17]. TB lymphadenitis occurs more frequently in women than in men [1].

Previously, TB lymphadenitis was considered a disease of childhood; however, the peak age of onset in developed countries has shifted from childhood to ages 20 to 40 years [18]. In contemporary series, the median age has been approximately 40 years in developed countries (range 1 to 88 years) [12,14,19].

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Tuberculous lymphadenitishttp://www.uptodate.com/contents/tuberculous-lymphadenitis?topicKey...In developing countries where TB is endemic, extrapulmonary TB occurs in up to 60 percent of HIV-infected patients with TB and is frequently accompanied by signs of pulmonary involvement [20-22]. Most extrapulmonary TB cases (including TB lymphadenitis) occur among patients with HIV at CD4 counts