Abdominal pain is one of the most common complaints in childhood and one that frequently requires urgent evaluation in the office or emergency department. The cause is typically a self-limited minor condition, such as constipation, gastroenteritis, or viral syndrome . The challenge for the clinician is to identify those patients with abdominal pain who have either serious, potentially life-threatening conditions, such as appendicitis or bowel obstruction (as can occur from volvulus, intussusception, or adhesions), or infections that require specific treatment (ie, streptococcal pharyngitis or pneumonia) (table 1). The likely diagnosis is often suggested by the child's age and clinical features (ie, associated symptoms, past medical history, and physical examination).
The causes of acute abdominal pain in children will be discussed in this review. The emergent evaluation of children with acute abdominal pain and the evaluation and management of children with chronic abdominal pain are discussed separately. (See "Emergent evaluation of the child with acute abdominal pain" and "Chronic abdominal pain in children and adolescents: Approach to the evaluation".)
NEUROLOGIC BASIS OF ABDOMINAL PAIN
Pain receptors in the abdomen include visceral receptors (located on serosal surfaces, within the mesentery, and within the walls of hollow viscera) and mucosal receptors. Visceral receptors respond to mechanical and chemical stimuli whereas mucosal receptors respond primarily to chemical stimuli.
Visceral pain is usually poorly localized. Most visceral digestive tract pain is perceived in the midline because of bilaterally symmetric innervation. In some conditions, such as appendicitis, precise localization of the pain may develop once the overlying parietal peritoneum (which is somatically innervated) becomes inflamed.
Pain originating in the viscera may sometimes be perceived as originating from a site distant from the affected organ. Referred pain usually is located in the cutaneous dermatomes sharing the same spinal cord level as the visceral inputs.