Back pain in children
BACK PAIN IN CHILDREN
Traditionally, back pain in children has been considered as being due to a potentially serious condition until proved otherwise. This concern arose because some cases of serious disease were missed in the past. However, it is now known that benign back pain in children and adolescents is more common than was once thought. The emphasis now is on establishing diagnostic protocols that are accurate, inexpensive and, most importantly, less invasive than those which were thought necessary in the past. This does not detract from the fact that back pain in children remains a significant clinical challenge.
However, it is known that despite extensive investigation, the proportion of children who are afforded a diagnosis at the end of the day is small. One study reported that 78% of children with back pain were not given a diagnosis after extensive investigation. A balance therefore needs to be struck
- Nonspecific back pain in children is increasingly prevalent. It increases with age and is more common in girls than in boys
- However, back pain is much less common than in adults, with fewer than 30% of children and adolescents reporting back pain and very few presenting to doctors with their pain
- Overuse and back strain or musculoligamentous injury
- Disc problems: disc herniation, Scheuermann’s disease
- Vertebral fractures
Younger children and older children
- Infection – usually in those aged under 10 years:
- Retroperitoneal infection
- Bone tumours – primary osseous neoplasms are rare. The most common are Ewing’s sarcoma, aneurysmal bone cyst, osteoblastoma (considered benign but can be locally aggressive), osteoid osteoma and primary lymphoma.
- Tumours of the spinal cord – eg, ependymoma.
- Congenital disorders of the spine – eg, scoliosis.
- Systemic disease – eg, sickle cell disease.
- Good clinical assessment will diagnose most causes of pain.
- The younger the child and the longer the history, the more likely it is that a serious underlying condition is responsible for the symptoms.
- An algorithmic approach to paediatric back pain has been tested.
It is essential to take a careful history. This should incorporate:
- Characteristics of pain, including duration, severity, radiation of pain, disturbance of sleep and activities and associated and exacerbating factors.
- Accompanying symptoms – eg, fever, weight loss, neurological symptoms (weakness, numbness, gait disturbance, bowel and bladder dysfunction).
- Past medical history – eg, previous episodes of neck or back pain, arthritis, trauma.
- Family history – eg, arthritis, scoliosis.
- Psychological history – eg, depression aggravating back pain or back pain causing depression. See separate article Depression in Children and Adolescents.
- Social history – eg, carrying school bags, school activities, sports activities (especially contact sports, gymnastics, diving, bowling in cricket).
See also separate article Examination of the Spine. Examination should include:
- Localisation and evaluation of pain.
- Tenderness (site of maximal tenderness).
- Inspection (to detect deformity, wasting, kyphosis and scoliosis).
- Neurological examination (including power, tone, reflexes, sensation).
- One study reported that painless hyperextension combined with negative imaging closely correlated with a diagnosis of mechanical back pain.
Clinical indicators of serious pathology
- Age under four years
- Symptoms persisting for more than four weeks
- Interference with function
- Systemic features (fever, weight loss)
- Worsening pain
- Neurological features
- Recent onset of scoliosis
Persistent back pain in children can usually be diagnosed by history, examination and relatively simple tests (blood tests, plain radiography, bone scans). In the absence of indications for urgent referral (see ‘Referral’, below), initial assessment can be performed in general practice.
- Blood investigations might include FBC, ESR and CRP, rheumatoid factor and other rheumatological autoantibody tests (may be indicated if arthritis is suspected), U&Es, LFTs, amylase.
- Imaging: plain X-rays, including posterior-anterior (PA) and lateral, CT scanning, MRI scanning and single-photon emission computed tomography scanning (SPECT).
It is important to pursue a diagnosis. It is more usual to make a diagnosis of a specific cause in children and nonspecific back pain is a diagnosis of exclusion. When considering the aetiology and diagnosis of back pain consider:
- Scheuermann’s disease.
- Vertebral fractures.
- Lumbar spondylolysis (a unilateral or bilateral stress fracture of the narrow bridge between the upper and lower pars interarticularis):
- This causes low back pain quite commonly in adolescent athletes.
- Consider especially age 11-17 years.
- Occurs in sports with repetitive flexion and extension. Sports include gymnastics, diving, weightlifting, rowing, tennis, cricket and football.
- On examination, patients may have a waddling gait associated with hamstring tightness and a lordotic posture.
- The most memorable test for spondylolysis is the stork test (standing on one leg and bringing the back into lumbar extension elicits pain on the side ipsilateral to the pars interarticularis lesion).
- SPECT scanning is the most sensitive imaging test to detect spondylolysis.
- In some cases, spondylolysis persists to become spondylolisthesis (25% of cases). This occurs particularly in adolescent athletes.
- It is often asymptomatic but symptoms typically occur at the time of the growth spurt.
- It usually causes focal pain aggravated by certain activities (particularly spinal extension and, to a lesser degree, rotation).
- Rest improves pain. Pain is sharp, mild-to-moderate in intensity and can radiate to the buttock.
- The classic Phalen-Dickson sign (knee-flexed, hip-flexed gait) may occur in spondylolysis, especially if there is associated spondylolisthesis.
- Pyogenic vertebral osteomyelitis is the most common form of vertebral infection.
- Children usually present with abrupt onset of malaise, fever and back pain with stiffness, restricted movement, guarded walking and spinal tenderness.
- Leukocytosis, raised ESR and CRP are usual findings.
- CT scanning detects earlier than plain radiographs and MRI scanning is better still.
- Radionucleotide scanning, especially technetium combined with gallium, demonstrates virtually all pyogenic vertebral infections.
- Ankylosing spondylitis
- Tumours: bone tumours may present with pain and can be demonstrated on plain radiographs.
- Overuse, nonspecific back pain and musculoligamentous injury. This settles quickly with rest but caution is due particularly with respect to the diagnosis of spondylolysis.
About half of adolescent patients will have self-limiting, short-lived pain caused by overuse or strain. Management should incorporate:
- Confirmation of diagnosis and exclusion of serious pathology.
- Simple analgesia.
- Preventative measures with:
- Advice and education
For those patients more likely to have a serious pathology, early assessment to establish a differential diagnosis and hence urgency of referral is important. All will require referral and subsequent management will vary according to the underlying diagnosis.
The National Institute for Health and Care Excellence (NICE) recommends examination, investigation and possible referral for children with persistent back pain, as this can be a sign of cancer (NICE comments that ‘persistent’ depends on the clinical situation but suggests 4-6 weeks as a rule of thumb)
In other situations, referral should depend on clinical judgement but features that may cause concern might include:
- Worsening pain
- Persistent fever
- Neurological deficit
- Pain accompanied by stiffness
- A variety of complications can arise depending on the diagnosis. In general terms complications may be reduced or prevented by timely diagnosis.
- Complications include delayed diagnosis (with possible implications for management and prognosis) and psychosocial difficulties, such as exclusion from sport and depression.
This is determined by the underlying diagnosis.
Posture and psychosocial factors are important in back pain. Back education programmes are effective in reducing risk factors for long-term back pain but whether this benefit is sustained in later life requires further investigation.
- Backpacks can cause back pain if they are too heavy or the weight is carried unevenly (over one shoulder). The following should be advised:
- Load the minimum weight possible
- Carry a school backpack on two shoulders
- Correct the belief that school backpack weight does not affect the back
- Use of a locker at school
- Apart from swimming, the evidence supporting the benefits of sport in preventing back pain in children is sparse. Both intense activity and inactivity are associated with back pain.