Somatisation in a child (Functional abdominal pain)

Question 1

Define somatisation.

Answer 1

Abdominal pain of sufficient severity to interfere with daily activities without demonstrable evidence of a pathological condition.

Question 2

Explain the aetiology of somatisation.

Answer 2

Intermittent or continuous. Rome III criteria classification. Chronic pain > 1-2/12. Often misdiagnosed. Unknown exact aetiology; proposed mechanisms include:

• Enteric nervous system (ENS): Abnormal bowel reactivity to physiological stimuli (meal, luminal distention, hormonal changes), noxious stressful stimuli (inflammatory processes) or psychological stressful stimuli (parental separation, anxiety).
• Visceral hyperalgesia: Decreased pain threshold to changes in intraluminal pressure secondary to sensitization of afferent nerves by infections, allergies or primary inflammatory diseases.
• Biopsychosocial model: Child’s response to biological factors, governed by an interaction between the child’s temperament and the family/school environments.

Question 3

What are risk factors associated with somatisation?

Answer 3

Possible psychological disturbances.

Question 4

What is the pathophysiology of somatisation?

Answer 4

Organic disease biopsy microscopy: Marked basal layer hyperplasia, vascular ectasia and numerous epithelial eosinophils/lymphocytes (oesophagus), lymphoid aggregates (gastric antrum/fundus), crypt hyperplasia, moderate/marked villous atrophy, or increased intraepithelial lymphocytes (duodenum).

Question 5

Summarise the epidemiology of somatisation.

Answer 5

4-25% of school-aged children.

Question 6

What are the signs and symptoms of somatisation?

Answer 6

Functional abdominal pain needs to be distinguished from anatomical, infectious, inflammatory or metabolic causes of abdominal pain. May present with symptoms typical of functional dyspepsia, IBS, abdominal migraine or functional abdominal pain syndrome.

• IBS: Pain is often worse before and relieved by defaecation, stools contain excess mucus, children experience bloating, sensation of incomplete defaecation and constipation.
• Functional dyspepsia: Epigastric pain, postprandial vomiting, early satiety and GOR.
• Abdominal migraine: Paroxysmal pain with anorexia, N&V +/- pallor. Maternal migraine history.
• Functional abdominal pain syndrome (FAPS): FAP without characteristic of dyspepsiea, IBS or abdominal migraine.

Question 7

What are the investigations associated with somatisation?

Answer 7

If symptoms and signs indicate an organic cause: involuntary weight loss, deceleration of linear growth, gastrointestinal blood loss, significant vomiting, chronic severe diarrhoea, persistent RUQ/RIF pain, unexplained pyrexia, FHx IBD. Endoscopy with negative biopsies may exclude organic disease. USS for RIF/RUQ pain (gallstones/ovarian cyst/appendiceal pathology).

Question 8

What is the management of somatisation?

Answer 8

Supportive: Somatisation diagnosis should be made as a positive diagnosis (not exclusion), therefore limiting unnecessary investigation. Careful explanation, headache analogy (functional disorder rarely associated with serious disease), establishment of reasonable goals, reassurance of absence of organic disease.

Psychological: CBT and biofeedback; some supporting evidence. General positive effect on children with true functional abdominal pain.

Medical: Time-limited use of medications; H2-antagonists/PPI, peppermint oil enteric-coated capsules can aid symptom control. Poor evidence base.

Question 9

What are the complications associated with functional abdominal pain?

Answer 9

Psychological impact and changed family dynamics.

School absences may interfere with education.

Question 10

What is the prognosis of functional abdominal pain?

Answer 10

Usually self-limiting (>50% spontaneously resolve) although may continue into adulthood as IBS.