User:Drexden/Tuberculous lymphadenitis

Lead Section
Peripheral tuberculous lymphadenitis (or tuberculous adenitis) is a form of tuberculosis infection occurring outside of the lungs. In general, it describes tuberculosis infection of the lymph nodes, leading to lymphadenopathy. When the cervical lymph nodes are affected, it is commonly referred to as "Scrofula ." A majority of tuberculosis infections affect the lungs, and extra-pulmonary tuberculosis infections account for the remainder; these most commonly involve the lymphatic system. Although the cervical region is most commonly affected, tuberculous lymphadenitis can occur all around the body, including the axillary and inguinal regions.

Epidemiology
The exact prevalence of tuberculous lymphadenitis varies between countries and regions, with higher rates seen in developing countries. Studies have shown that women may have higher rates of tuberculous lymphadenitis compared to men. Conversely, men appear to have higher rates of pulmonary tuberculosis. In regions where tuberculosis is not endemic, many of those affected with tuberculous lymphadenitis are foreign-born. In general, tuberculous lymphadenitis is more frequently documented in immunocompromised patients, such as those with uncontrolled HIV.

Causes
Mycobacterium tuberculosis is the most common cause of both pulmonary tuberculosis and tuberculous lymphadenitis. Historically, transmission of Mycobacterium bovis from dairy consumption was another frequent cause of tuberculous lymphadenitis, but incidence has drastically decreased in developed countries since the advent of pasteurization and other efforts to prevent bovine tuberculosis.

Signs and Symptoms
The typical presentation of tuberculous lymphadenitis involves a gradual and usually painless swelling of the affected lymph nodes (termed lymphadenitis). Duration of symptoms can vary, and ranges between weeks to months following initial onset. Unilateral lymph node involvement accounts for the majority of cases, and involvement of the cervical lymph nodes is the most common.

In addition to swollen lymph nodes, the person may experience mild fevers, decreased appetite, or weight loss. Pulmonary tuberculosis infection may co-occur with tuberculous lymphadenitis and account for additional symptoms such as cough.

Diagnosis
The gold standard for diagnosis of tuberculous lymphadenitis is obtaining a culture, though results may take weeks. A positive acid-fast bacteria (AFB) stain can support the diagnosis. Other possible methods include nucleic acid amplification tests, fine needle aspiration (FNA), or excisional biopsy, the most invasive method.

Supplementary studies to aid in diagnosis include tuberculin skin tests, interferon-gamma release assays, or chest X-rays.

Treatment
Currently accepted treatment of tuberculous lymphadenitis involves an anti-tuberculosis medication regimen for at least 6 months. This includes isoniazid, rifampin, pyrazinamide, and ethambutol depending on susceptibility to the drug.

While surgical removal of the affected lymph nodes alongside antibiotic therapy has shown some efficacy, there are no formal recommendations for surgery to treat tuberculous lymphadenitis.