2 Clinical presentation of childhood tuberculosis

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Contents

• Objectives
• Early presentation of tuberculosis
• Pulmonary tuberculosis
• Extrapulmonary tuberculosis
• Enlarged tuberculous lymph nodes
• Tuberculous meningitis
• Abdominal tuberculosis
• Tuberculosis of bone and joints
• Disseminated tuberculosis
• Scoring systems to identify tuberculosis
• Case studies

Objectives

When you have completed this unit you should be able to:

• Recognise the general symptoms and signs of tuberculosis.
• List the symptoms and signs of pulmonary tuberculosis.
• Describe the appearance of tuberculous lymph node enlargement.
• Clinically diagnose tuberculous meningitis.
• Clinically diagnose abdominal tuberculosis.
• Clinically diagnose spinal tuberculosis.
• Clinically diagnose disseminated tuberculosis.

Early presentation of tuberculosis

2-1 How is the clinical diagnosis of tuberculosis made?

The clinical diagnosis of tuberculosis depends on the following five steps:

1. Having a high index of suspicion.
2. The patient being in contact with an adult with pulmonary tuberculosis.
3. Taking a careful history.
4. Completing a full general examination.
5. Requesting special investigations.

2-2 What would make you suspect that the child may have tuberculosis?

Always suspect tuberculosis if one or more of the following are present:

• A history of close contact with someone suffering from tuberculosis in the family or household, especially if recently diagnosed.
• Poor, overcrowded living conditions.
• The child has HIV infection.
• The child is losing weight or is severely malnourished.
• The child has a chronic, persistent cough.
• The child has pneumonia which does not respond to antibiotics.
• The child has fever for more than 14 days and is not responding to antibiotics.
• The child is unwell with vomiting and a decreased level of consciousness, with or without convulsions.

Having a high index of suspicion that the child has been in close contact with someone with tuberculosis in a community, especially if they live in the same household, is often the most important step in making the diagnosis. A high index of suspicion is very important in the early diagnosis of tuberculosis, as tuberculosis may present in many different ways and may be confused with a wide range of other diseases.

Suspecting tuberculosis is important in making the diagnosis.

2-3 What are the symptoms and clinical signs of tuberculosis?

• The early symptoms and signs of tuberculosis are often vague and non-specific, making the diagnosis difficult. These general symptoms and signs are caused by tuberculosis at any site in the body. Children are usually asymptomatic in the early stages of tuberculosis.
• The later signs of tuberculosis usually depend on which organ or organs are infected. The organ most commonly affected is the lung (pulmonary tuberculosis).

Symptoms are what the child or parent complains of, while signs are what you observe.

2-4 What are the early general symptoms and signs of tuberculosis?

• Failure to thrive with poor weight gain or weight loss. Children with tuberculosis are often thin and undernourished. This may first be noticed when the child’s weight is plotted in the Road-to-Health booklet.
• Feeling generally unwell with loss of appetite, apathy and fatigue, are common symptoms. In young children the parents complain that the child is not as playful as usual. Older children may complain of feeling weak and tired.
• A fever for more than two weeks when no other cause of fever can be found and there is no response to antibiotics. Fever due to viral infections usually lasts less than seven days.
• Nights sweats, especially if the child is so wet that their clothes need to be changed. However severe night sweats are not common in young children with tuberculosis.

Children with tuberculosis have usually been unwell for a few weeks when they first present. Unlike the sudden onset in acute bacterial or viral infections, the symptoms and signs of tuberculosis usually develop over a number of days or weeks.

There are often no clinical signs on examination in the early stages of tuberculosis.

A detailed history is very important when considering a diagnosis of tuberculosis as the history is often the most important clue to the correct diagnosis. Therefore always consider tuberculosis in a child with a chronic cough, weight loss, failure to thrive or unexplained fever for more than two weeks, especially if there is an adult with a chronic cough or known pulmonary tuberculosis in the family.

A careful history is very important in the diagnosis of tuberculosis.

Pulmonary tuberculosis

2-5 What are the symptoms of pulmonary tuberculosis?

These symptoms and signs are important as pulmonary tuberculosis is the commonest form of tuberculosis in children and adults.

• In addition to the early general symptoms and signs, the most important sign of pulmonary tuberculosis is a persistent cough lasting more than two weeks. The cough may be dry or productive and shows no signs of improving.
• The enlarged hilar nodes may press on a bronchus (airway) causing wheezing, cough or stridor. The wheeze does not respond to inhaled bronchodilators.
• Shortness of breath and fast breathing are not common in children with tuberculosis. Chest pain and blood-stained sputum (haemoptysis) may be present in adolescents, but are rare in children.

A persistent cough lasting longer than two weeks is an important symptom of pulmonary tuberculosis.

2-6 What are the clinical signs of pulmonary tuberculosis?

• Usually there are no abnormal clinical signs on examination of the chest. Therefore, a lack of signs does not exclude the diagnosis of tuberculosis.
• There may be signs of pneumonia (fast breathing, crackles and decreased air entry).
• There may be wheezing due to airway compression by enlarged hilar lymph nodes. The wheeze does not respond to bronchodilators.
• There may be signs of a pleural effusion (dullness over one side of the chest with poor air entry and possibly shortness of breath), especially in older children and adolescents.
• Often children with extensive tuberculosis are not acutely ill, do not require supplementary oxygen and have very few clinical signs on chest examination but have extensive changes on chest X-ray.

Commonly there are no clinical signs on chest examination in children with pulmonary tuberculosis.

Children with tuberculosis may also have symptoms and signs of HIV infection.

Extrapulmonary tuberculosis

2-7 What is the clinical presentation of extrapulmonary tuberculosis?

This depends on whether TB bacilli spread to only one organ (e.g. the meninges), or to two or more organs at the same time.

Enlarged tuberculous lymph nodes

2-8 What is the common site of enlarged tuberculous lymph nodes?

Enlarged lymph nodes (lymphadenopathy) due to tuberculosis occur most commonly in the neck (cervical nodes).

Enlarged cervical lymph nodes may be due to tuberculosis.

2-9 What are important signs of enlarged cervical lymph nodes?

Often the mother first notices that the child has lumps in the neck. At first the nodes are typically firm and non-tender on examination. Later they may feel matted (stuck together). Enlarged tuberculous lymph nodes may lead to complications.

2-10 What are the complications of enlarged cervical lymph nodes?

The lymph nodes may become tender and soft due to inflammation and the breakdown of tissue in the node (lymphadenitis) to form a lymph node abscess. Later lymph nodes may become attached to the skin and discharge the soft (caseous) material onto the skin. This results in a fistula. With healing, tuberculous fistulas leave scars.

2-11 What is a common cause of enlarged lymph nodes in the axilla?

Enlarged lymph nodes in the axilla (arm pit) are common a few weeks or months after a BCG immunisation on the upper arm on the right side. This is not caused by tuberculosis but results from the BCG immunisation in young children. Complications of enlarged axillary lymph nodes due to BCG are common in children with HIV infection.

Tuberculous meningitis

2-12 What is tuberculous meningitis?

Infection of the membranes which cover the brain (the meninges) by TB bacilli.

2-13 What is the clinical presentation of tuberculous meningitis?

The symptoms and signs of tuberculous meningitis are:

• Drowsiness, irritability and vomiting in a child who has been unwell for a few days.
• Depressed level of consciousness.
• Older children may complain of headaches.
• Convulsions.
• The fontanelle may be full with a rapidly increasing head circumference.
• Muscle weakness progressing to one-sided paralysis (hemiplegia) due to a stroke.
• On examination there may be neck stiffness.

A depressed level of consciousness is an important sign of tuberculous meningitis.

It is important to suspect tuberculous meningitis in any child with drowsiness, headache and vomiting. The onset of symptoms and signs are often slow over a number of days. A depressed level of consciousness, convulsions and paralysis are late and dangerous signs.

2-14 Do children with tuberculous meningitis always die?

It depends on whether the diagnosis is made early or late. Full recovery is possible after an early diagnosis. However children who present late with depressed level of consciousness and signs of a stroke often die despite treatment. Children who survive after the development of late signs may survive with permanent disability (blindness, deafness, cerebral palsy, mental retardation and hydrocephalus).

It is very important to suspect TB meningitis in any child with unexplained drowsiness, headache or vomiting so that an early diagnosis can be made and immediate treatment started.

Abdominal tuberculosis

2-15 What is abdominal tuberculosis?

Tuberculosis of one or more organs in the abdomen. It is usually due to the spread of TB bacilli from the lungs. Newborn infants may have abdominal tuberculosis as a result of TB bacilli spreading from the infected placenta.

2-16 What are the clinical signs of abdominal tuberculosis?

The most common presentation of abdominal tuberculosis is:

• Abdominal distension (swelling). This may be due to fluid (ascites) or enlarged lymph nodes. The liver and spleen may also be enlarged.
• Abdominal pain may be present.
• Weight loss.
• Fever with no obvious cause.

Tuberculosis of bone and joints

2-17 What bones and joints may be infected with TB bacilli?

The most common sites are the spine (spinal tuberculosis) and large joints such as the hip, knee or ankle. However, any bone or joint can be infected.

2-18 When do children develop bone tuberculosis?

Bone tuberculosis (tuberculous osteitis) usually develops months to years after the primary TB infection. It is due to reactivation of TB bacilli that have been dormant in the bone ever since they were first carried there by blood spread from the lungs. Therefore it is uncommon in young children and usually seen in older children and adolescents.

2-19 What is the presentation of spinal tuberculosis?

Tuberculous osteitis of the spine usually occurs in the lower thoracic or upper lumbar vertebrae with:

• Local pain and tenderness
• Local deformity (gibbus)
• Spinal cord compression (difficulty walking and passing urine)

Any child with local pain and tenderness over the spine must be suspected of having spinal tuberculosis. A rapid onset of a gibbus (‘hump back’) is almost always due to tuberculosis.

Spinal tuberculosis presents with local pain and tenderness.

Disseminated tuberculosis

2-20 What is disseminated tuberculosis?

Disseminated tuberculosis occurs when TB bacilli spread throughout the body via the bloodstream as the immune system cannot contain them in the lung. This leads to tuberculosis in a number of organs other than the lungs, such as the meninges, abdominal lymph nodes, liver, spleen, bones and joints.

2-21 Which children are at high risk of disseminated tuberculosis?

• Children under the age of one year
• Children who have not had BCG immunisation
• Children with severe malnutrition
• Children with HIV infection

Disseminated tuberculosis is most often seen in infants.

2-22 What is the clinical presentation of disseminated tuberculosis?

• At first the child becomes generally unwell with loss of appetite, failure to thrive and fever.
• There may be a history of cough.
• The liver and spleen may be enlarged.
• There may be features of tuberculous meningitis.

2-23 Why is it important to diagnose disseminated tuberculosis as soon as possible?

Because these children become extremely ill and may die if not diagnosed and treated rapidly and correctly.

2-24 What is miliary tuberculosis?

Miliary tuberculosis is the spread of TB bacilli throughout both lungs. It is seen in some cases of disseminated tuberculosis and can be diagnosed on chest X-ray.

Note

The word ‘miliary’ comes from the Latin for millet seed as the X-ray in a child with miliary tuberculosis shows small spots throughout both lungs.

Scoring systems to identify tuberculosis

2-25 Can a scoring system be used to help make a clinical diagnosis of tuberculosis?

Scoring methods are available, but they are not very accurate in children, especially if HIV infection is also present. However, they are useful in identifying children who are at high risk of having tuberculosis and need to be referred for further evaluation and special tests.

Case study 1

A grandmother presents at a primary-care clinic with her 3 year old granddaughter. She gives a history that the child has a poor appetite, weight loss and fever for the past three weeks. The local general practitioner prescribed amoxicillin for a respiratory tract infection but this has not helped. The mother died of HIV infection a few months ago.

1. Why should you suspect tuberculosis?

Because the child has a number of the general symptoms which suggest tuberculosis (poor appetite with weight loss and prolonged fever). Failure to respond to the antibiotic treatment given for a bacterial respiratory tract infection also suggests tuberculosis.

2. What social history would be important?

It would be important to know if anyone in the home has tuberculosis or a chronic cough which may be due to undiagnosed tuberculosis. You should also ask about overcrowding and poverty.

3. Why is the history of the mother’s death important?

She might have died of tuberculosis complicating HIV infection. If the child is HIV infected this would greatly increase the risk of tuberculosis.

4. What clinical signs would you expect to find?

Often there are very few clinical signs early in tuberculosis. It would be important to weigh the child and plot the weight in the Road-to-Health booklet to assess weight loss. Signs of malnutrition and HIV infection should also be looked for.

5. Do children with tuberculosis often have night sweats?

No.

6. Would a scoring system be useful in diagnosing tuberculosis?

It would be more accurate to identify children who are at high risk of tuberculosis and need further investigation.

Case study 2

A 4 year old child presents with a chronic cough for the past month, together with feeling weak and tired. As the examination of the chest is normal, the medical officer assures the parents that the child does not have pulmonary tuberculosis.

1. Could this child have pulmonary tuberculosis?

Yes. A chronic cough, especially if not improving, should always suggest tuberculosis. There is not enough information to exclude tuberculosis.

2. Would a normal chest examination exclude pulmonary tuberculosis?

No, as children with pulmonary tuberculosis often do not have abnormal chest signs on examination.

3. What would be the likely cause if a wheeze was present?

If the child had no previous history of wheezing, it would be important to think of an enlarged hilar lymph node pressing on a large airway. If this were correct, the wheeze would not respond to an inhaled bronchodilator.

4. What would the likely diagnosis be if there was poor air entry and dullness to percussion on one side of the chest?

A pleural effusion. This might also cause shortness of breath.

5. How should this child be managed?

Further investigations are indicated to confirm or exclude a clinical diagnosis of tuberculosis.

Case study 3

A 10 year old girl is seen in the outpatient department of a district hospital with a swelling in her neck. Examination suggests enlarged cervical lymph nodes. There is no history of tuberculosis in the home.

1. How common are enlarged cervical lymph nodes in tuberculosis?

Cervical lymph node enlargement is common in children with tuberculosis.

2. What are the typical clinical findings?

Usually the lymph nodes are firm and painless, but may feel matted (stuck together).

3. What complication can occur in tuberculous lymph node enlargement?

The nodes may become painful and soft (lymphadenitis) and form an abscess or fistula which drains onto the skin.

4. What may cause enlarged axillary (arm pit) lymph nodes?

BCG immunisation on that side.

5. How do TB bacilli reach the cervical nodes?

By lymphatic spread from lymph nodes in the chest.

Case study 4

An ill six-month-old child presents with a two-week history of fever, poor feeding, drowsiness and irritability. A few hours back the child had a convulsion. The father started on TB treatment a month before.

1. What is the likely clinical diagnosis?

Tuberculous meningitis. The father is almost certainly the source of the infection.

2. How do TB bacilli reach the meninges?

They get there via the bloodstream. Tuberculous meningitis is usually seen in infants and young children, and occurs soon after the primary infection.

3. Is it important that this child has had a fit?

Yes, as this is a late and serious sign of tuberculous meningitis and increases the risk of death or permanent disability. Therefore it is important to make the diagnosis as soon as possible.

4. What is miliary tuberculosis?

Disseminated tuberculosis with widespread involvement of both lungs. These children are seriously ill.

5. What are important local signs of abdominal tuberculosis?

Abdominal pain and distension. Sometimes an enlarged liver and spleen may be palpated.

The five most important ‘take-home’ messages

1. Close contact with a person with untreated tuberculosis in the household is the most important clue to suspecting tuberculosis in a child.
2. Children who are unwell with a chronic cough or weight loss should be investigated for tuberculosis.
3. A normal clinical examination does not exclude tuberculosis in a child.
4. Tuberculous meningitis is a very serious form of tuberculosis and should be suspected in any child with lethargy, headache and vomiting.
5. Disseminated tuberculosis is most commonly seen in young infants and children with HIV infection or malnutrition.