Introduction

Abdominal pain is a common reason for children to attend an emergency department (ED), occurring in up to 5% of all presentations in some institutions.¹ Most commonly the underlying cause is non-surgical and surgery is required in only 1–7% of children who present with abdominal pain.^1,2 It is not possible to make a definitive diagnosis in all children with abdominal pain. In one study, as many as 15% of children presenting to emergency with abdominal pain did not have a specific diagnosis at their discharge. Some children arrive at the ED soon after the onset of symptoms and it may take time, expectant management and review before a diagnosis becomes clearer or the symptoms of a self-limiting cause resolve. It is important, however, to exclude causes of abdominal pain that may require early surgical consultation, observation or investigations within the ED.

The priorities in managing children presenting with abdominal pain are:

If a clear diagnosis cannot be reached in the ED, then exclusion of serious/life-threatening diagnoses is the priority. Subsequent disposition and follow up is dependent on various factors including: likelihood of a serious diagnosis; severity of the pain; availability of review; and psychosocial factors that may be contributory.

Pathophysiology

The sensation of abdominal pain is transmitted by either somatic or visceral afferent fibres.³ Visceral pain from visceral peritoneum is poorly localised, whereas somatic pain arising from parietal peritoneum or the abdominal wall is more localised. Referred pain also occurs due to visceral and somatic pathways converging in the spinal column. Two examples of referred pain are diaphragmatic irritation leading to pain at the shoulder tip due to convergence of visceral and somatic pathways at C4, and somatic pain from pneumonia leading to T10–11 pain sensed in the lower abdomen.³ Abdominal pain may occasionally be found to be psychosomatic in origin after a thorough assessment of alternative causes.

Aetiology

There is a broad range of causes of abdominal pain in children and one needs to initially keep an open mind regarding the diagnosis (Table 7.1.1). The age and sex of the child need to be considered, as well as features of the abdominal pain and associated symptoms, and examination findings to determine the diagnostic possibilities.

Table 7.1.1 Causes of acute abdominal pain in children

Inflammatory gastrointestinal Appendicitis Meckel’s diverticulum Mesenteric adenitis Gastroenteritis Food poisoning Peritonitis Peptic ulcer, gastritis Hepatitis Pancreatitis Inflammatory bowel disease Non-gastrointestinal Tonsillitis, pharyngitis Pneumonia (especially basal) Pericarditis Serositis Pyelonephritis, cystitis Pelvic inflammatory disease Intra-abdominal abscess Epididymitis Generalised Infectious mononucleosis Acute rheumatic fever Herpes zoster Intestinal obstruction Intussusception Volvulus Adhesions Incarcerated hernia Abdominal trauma See Section 3 Gall bladder Cholecystitis, cholelithiasis Haematological Leukaemia, lymphoma Haemolytic crisis Sickle cell disease Neuroblastoma, Wilms’ tumour Endocrine Diabetic ketoacidosis, hypoglycaemia Adrenal insufficiency Hyperparathyroidism Vasculitic Henoch–Schönlein purpura Periarteritis nodosa Kawasaki disease Renal Renal colic Hydronephrosis Nephrotic syndrome Miscellaneous Constipation Colic Toxic ingestion, e.g. lead Torsion–testicular/ovarian Ectopic pregnancy Dysmenorrhea, Mittelschmerz pain Mesenteric artery occlusion Hypokalaemia Acute intermittant porphyria Familial Mediterranean fever Abdominal migraine Psychosomatic – including abuse

Source: Adapted from Rudolph 1996.

Assessment

Each child needs initial assessment and triage with attention to securing the ABCs and providing appropriate early analgesia. This will help achieve a more reliable examination. A detailed history and thorough, gentle, and age-appropriate examination need to be performed.

History

In considering a child who has presented with abdominal pain with no history of trauma, five important questions have to be addressed: