Appendicitis in Children

Diagnostic challenges of abdominal pain in children

Abdominal pain (abdominal pain) is an extremely common symptom in pediatrics, which is often functional in nature. The clinician's main task is to promptly rule out pathologies requiring emergency surgical intervention. Diagnosis is complicated by the fact that children and adolescents are often unable to accurately describe the localization, intensity, type, and frequency of pain.

Ultrasound is used as the first-line method for acute pain ultrasound, as the small amount of adipose tissue in children provides high detail of internal structures. Plain abdominal radiography (plain abdominal radiography) after the neonatal period is indicated only when free gas (free air) or intestinal obstruction (ileus) is suspected.

Clinical presentation and age-related features

In children, acute appendicitis is the leading cause of acute abdomen syndrome. About 30–40% of patients do not present with classic symptoms, which greatly complicates diagnosis.

• Infants and preschool children: The disease runs an atypical course and progresses much faster. The pain is diffuse and not clearly localized in the right iliac fossa. General intoxication develops rapidly, repeated vomiting occurs early, and fever is higher than in older patients. Classical peritoneal signs (e.g., Shchetkin-Blumberg sign) may be poorly expressed. Due to anatomical features—a short omentum that poorly walls off the inflammation—diffuse peritonitis develops rapidly in infants, and the risk of perforation is extremely high due to delayed diagnosis.
• Older children and adolescents: The clinical picture is closer to the course of the disease in adults. Kocher-Volkovich sign is characteristic—migration of pain from the epigastric or periumbilical area to the right iliac fossa. Nausea, single vomiting, low-grade fever, localized muscle guarding of the anterior abdominal wall, and clearly positive peritoneal irritation signs gradually join.

Ultrasound diagnostics (primary method)

Ultrasound is the first-line method when inflammation of the appendix is suspected. It allows confirming, presuming, or ruling out the diagnosis, drastically reducing the rate of false-positive appendectomies. The method is fast, inexpensive, and carries no radiation exposure. The study is performed using a high-frequency linear transducer with the graded compression technique.

Key ultrasound criteria:

• Visualization of a tubular, blindly ending, and non-compressible structure.
• Maximum outer diameter of the appendix exceeds 6 mm.

Additional signs:

• Changes in wall blood flow: hyperemia in active inflammation or hypoperfusion in developing necrosis.
• Hyperechogenicity of the surrounding inflamed mesenteric fat.
• Presence of an appendicolith (appendicolith), which produces a distinct acoustic shadow (echo shadow) on longitudinal scanning.

With the development of necrosis and perforation, free fluid in the abdominal cavity is detected on ultrasound, and only two remaining wall layers may be differentiated on an axial slice of the necrotic appendix.

Role of CT and differential diagnosis

Computed tomography (CT) is rarely used in routine pediatric practice due to high radiation exposure. Its use is justified only in diagnostically challenging situations when ultrasound has been uninformative, but the clinical picture dictates the need for surgical intervention. CT is also indicated when a complicated course is suspected—specifically, the formation of a periappendiceal abscess.

When performing differential diagnosis, it is important to remember ultrasound mimics of acute appendicitis. These include terminal ileitis and acute salpingitis (found in adolescent girls). In addition, anatomical variations should be considered: with a retrocecal location, an inflamed appendix can provoke the formation of subcapsular liver abscesses.

Appendicitis as a secondary complication

Inflammation of the appendix can occur not only as an independent acute surgical pathology, but also as a complication of other infectious or parasitic diseases:

• Measles: Appendicitis refers to specific gastrointestinal lesions occurring against the background of measles infection (along with stomatitis, enteritis, and colitis).
• Enterobiasis: Migration of the pathogen (pinworms) can provoke an inflammatory process in the appendix, which requires a thorough history taking regarding intense perianal itching in the evening and at night.

Class and exam questions

What else to study on this topic

• Mesenteric lymphadenitis as a cause of abdominal pain
• Differential diagnosis of abdominal syndrome in intestinal infections (yersiniosis, campylobacteriosis)
• Pseudoabdominal syndrome in epidemic myalgia (Bornholm disease)
• Gastrointestinal complications of enterobiasis and trichuriasis
• Diagnostic imaging of cloacal anomalies and assessment of common channel length

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.