History and exam

Key diagnostic factors

common

presence of risk factors

Key risk factors include: exposure to TB; born in Asia, Latin America, or Africa; HIV infection; immunosuppressive medicines; haematological or head/neck malignancy; ESRD; apical fibrosis; and very young age.

enlarged lymph node

Painless and gradual enlargement of unilateral or bilateral cervical or supraclavicular nodes over a period of weeks; nodes are typically firm.

Other presentations include painful or fluctuant nodes that may have drainage. Nodes may rarely be located in axillary or inguinal regions.[74][75]

Concomitant pulmonary TB may also be seen.

pleuritic chest pain

Present in up to 75% of patients with pleural TB.[75]

skeletal pain

Pain is common in skeletal TB and its location depends on the site of involvement.

Pain may evolve over weeks to months.

In Pott's disease, kyphosis may be present and focal tenderness may be present.

If the hip or knee is involved, the patient may complain of pain with walking and local swelling may be present.

If untreated, cold abscesses may form that are not tender or erythematous and are more common in HIV-positive patients. If these rupture, a draining sinus tract forms.[52]

urinary symptoms

Seen in GU TB. Includes dysuria, haematuria, and urinary frequency.

abdominal swelling

In peritoneal TB, swelling seen in over 90% of patients.

The classic doughy abdomen is associated with the chronic fibroadhesive form and is rarely seen.

abdominal pain

Diffuse pain may be seen in 75% of patients with TB peritonitis.

In patients with TB enteritis, pain is present in 80% to 90%, most commonly in the right lower quadrant (RLQ). A palpable mass may be present.

uncommon

headache

Seen in TB meningitis.

Other diagnostic factors

uncommon

cough

Active pulmonary TB is found in 15% to 20% of patients with EPTB. Higher rates of pulmonary involvement along with EPTB are seen in children, patients with disseminated disease, and those with pleural TB (up to 55%); patients with pleural TB often have a non-productive cough (70%).[76][77][78]

altered mental status

Seen in TB meningitis.

neurological symptoms

Cranial nerve involvement results from TB meningitis, as the process is located primarily at the base of the brain.

Peripheral nerve symptoms may result from vertebral involvement with cord compression. May include numbness, weakness, or paralysis. Vertebrae in thoracolumbar region most commonly involved.

hepatomegaly

May be seen in up to one-third of patients with disseminated TB. May also have splenomegaly.[16]

abnormal chest examination

Chest examination may be abnormal if pulmonary TB also present or if pleural disease.

Possible findings include a friction rub, crackles, decreased breath sounds, or dullness to percussion.

fever

May be seen in one third of patients with EPTB, although fever may be more common in HIV-positive patients and peritoneal TB.

Fever is very common in disseminated TB (up to 95% of patients). EPTB can be considered in patients with fever of unknown origin (FUO).[77][78]

weight loss of more than 10% body weight

Common in disseminated TB (60%) and in HIV-positive patients.[77][78]

anorexia

Common in disseminated TB and in HIV-positive patients.[77][78]

malaise

May be seen in 15% to 30% of patients.[77][78]

night sweats

If present, usually drenching. Common in disseminated TB.[78]

dyspnoea

May be seen in disseminated TB.

asymptomatic

Particularly patients with GU TB, who may be suspected on routine urinalysis.

erythema nodosum and erythema induratum

Painful raised erythematous nodules over pretibial region or on the calves.

Risk factors

strong

exposure to TB

Exposure to an infectious case (i.e., pulmonary or laryngeal TB) is necessary but not sufficient for development of TB. Among household contacts, about one third will acquire latent TB infection and 1% to 2% will have active TB disease. Persons with recently acquired infection (e.g., new TB skin test conversion) have an increased risk of developing active TB, although this relationship holds less strong for EPTB compared with pulmonary TB.[20][21]

born in Asia, Latin America, or Africa

These are high-risk regions, particularly if immigration occurred within the prior 5 years. People from Southeast Asia and India are at higher risk for TB lymphadenitis.[22][23]

HIV infection

HIV infection increases the risk for both progression to primary disease and reactivation of latent disease. The risk for reactivation in an HIV-positive patient with latent TB infection is up to 10% per year, as opposed to a 10% lifetime risk in HIV-negative people. Extrapulmonary manifestations of TB are more common in HIV, and patients are at a higher risk for central nervous system TB.[3][24][25][26][27]

immunosuppressive medicines

Especially systemic corticosteroids and tumour necrosis factor (TNF) antagonists. Risk with corticosteroids increases with increasing doses (odds ratio 7.7 for >5 mg per day of prednisolone) and varies with underlying condition. Patients receiving TNF antagonists are at 2-20 times higher risk for TB; more than 50% of TNF antagonist-related TB cases will be extrapulmonary.[28] The risk for TB with infliximab is greater than etanercept. Relative risk following organ transplantation is 20- to 74-fold higher.[29][30]

haematological or head/neck malignancy

Patients with haematological malignancy and head-and-neck cancer have a higher risk than people without malignancies.[31] The risk with other types of cancer has not been determined.

end stage renal disease

Patients on haemodialysis are at increased risk of EPTB. Patients on peritoneal dialysis are at increased risk for peritoneal TB.[15]

apical fibrosis

Patients whose chest x-ray shows fibrotic changes consistent with prior pulmonary TB are at higher risk for developing active disease again (estimated risk 0.3% per year).[32]

very young age

The very young (<5 years) are at increased risk for progression to disease. EPTB is more common in younger patients. Disseminated TB is seen in higher rates in patients <14 years.[3][34]

weak

intravenous drug use

Even without HIV infection.[33]

female sex

Odds ratio for development of EPTB compared with pulmonary TB is 3.69.[20]

Asian, black, and Native American ethnicity

EPTB is more likely in Asian, black, and Native American people than in white people.[34]

malnutrition

Includes people with low body weight (<90% of ideal body weight), coeliac disease, and history of gastrectomy. Risk higher in patients who have undergone jejunoileal bypass.

alcoholism

Hard to separate from other risk factors.

diabetes

A relative risk of 2 to 4 if uncontrolled.

cirrhosis

Increased risk for peritoneal TB.[15]

high-risk congregate settings

Resident or employee of correctional facility, homeless shelter, or nursing home.

low socioeconomic status

Multivariate models suggest at least half the risk attributed to ethnicity (black, Hispanic, Native Americans) may be due to low socioeconomic status.[35]

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