Approach to acute abdominal pain (pediatrics): Clinical sciences

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Introduction 0:00–0:36

Acute abdominal pain is a common presenting concern in pediatric patients. While severe abdominal pain combined with abdominal rigidity, rebound, or guarding suggests a condition requiring urgent surgical intervention, most underlying causes of acute abdominal pain in children are transient and non-life-threatening.
Acute abdominal pain can be caused by gastrointestinal, urinary, pelvic, and neurologic or musculoskeletal conditions. When a pediatric patient presents with acute abdominal pain, you should first perform an ABCDE assessment to determine if they’re stable or unstable.

Unstable patient 0:36–2:10

If unstable, stabilize the airway, breathing, and circulation. Next, obtain IV access, begin fluid resuscitation, and continuously monitor vital signs.
Provide supplemental oxygen if needed, ensure that the patient does not take anything by mouth, and consider placing a nasogastric tube.
Finally, obtain an emergency surgical consultation and administer broad spectrum IV antibiotics. Once you’ve initiated acute management, perform a focused history and physical examination.
The history will reveal a sudden onset of severe abdominal pain, and the physical exam will often demonstrate abdominal tenderness, rebound, and guarding, possibly with abdominal distension and rigidity.
These peritoneal signs indicate an acute “surgical” abdomen, which requires immediate surgical intervention. Here’s a high-yield fact!
Appendicitis is the most common cause of a surgical abdomen in childhood, but other significant causes include intussusception, intestinal malrotation with volvulus, and incarcerated inguinal hernia.
Remember that blunt abdominal injury and nonaccidental trauma can cause intraperitoneal bleeding and visceral damage, both of which can present with acute abdominal pain in the absence of obvious external signs.
Now that we’ve discussed unstable patients, let’s move on to stable ones. First, perform a focused history and physical examination.

Stable patient 2:10–2:34

The history will reveal an acute onset of pain; occasionally with nausea, vomiting, or fever; while the physical exam will demonstrate abdominal tenderness.
Continue your evaluation by assessing your patient’s stooling pattern. Let’s start with patients who report increased stooling frequency.

Acute gastroenteritis 2:34–3:52

In this case, consider acute gastroenteritis. In addition to loose, watery stools, these patients often report crampy abdominal pain, as well as nausea, vomiting, anorexia, and fever.
There might also be a known sick contact or a history of recent travel. The exam often demonstrates abdominal tenderness.
Keep in mind that presentation may vary by age. Some patients, especially smaller children, may show signs of dehydration like dry mucous membranes and decreased skin turgor.
While acute gastroenteritis is usually a clinical diagnosis, if the diagnosis is uncertain, you can order stool viral antigen testing or a stool culture and microscopic examination.
If any of these tests are positive, you can confirm acute gastroenteritis, which can be caused by norovirus and rotavirus, as well as bacteria such as E.
coli, Campylobacter, and Salmonella. Here’s a clinical pearl!
Acute abdominal pain can also be caused by non-gastrointestinal infections, such as pneumonia and group A Streptococcal pharyngitis.
Next, let's discuss cases in which stooling frequency is decreased, which should make you consider constipation. Patients will report infrequent bowel movements, straining or pain during defecation, and hard stool consistency.

Acute constipation 3:52–4:32

The exam may demonstrate mild abdominal distension, a palpable stool mass in the lower abdomen, and occasionally, anal fissures.
In this case, you can diagnose acute constipation. Here’s another clinical pearl!
Acute gastroenteritis and acute constipation are the most common causes of acute abdominal pain in children. Now, let’s talk about cases in which there’s no change in the patient’s stooling pattern.

Urinary tract infection 4:32–6:00

Here, you should assess for signs and symptoms suggesting urinary tract pathology. In the case of urinary tract infection or UTI, infants under 2 months of age might have foul-smelling urine and irritability, while older children may describe dysuria, urgency, and frequent urination.
Physical exam might reveal an elevated temperature; as well as suprapubic or costovertebral angle tenderness. These findings should lead you to consider a urinary tract infection and obtain a CBC, urinalysis, and urine culture.
If the CBC reveals leukocytosis; the urinalysis is positive for white blood cells, as well as positive leukocyte esterase, and sometimes positive nitrites; and a urine culture grows more than 50,000 colony-forming units per milliliter of a single bacterial species, diagnose a UTI.
Here’s another clinical pearl! It can be difficult to differentiate cystitis from pyelonephritis, especially in children under 2 years of age.
Because a UTI can progress quickly, you should initiate empiric antibiotics as soon as you suspect one. Be sure to select antibiotics that cover enteric bacteria like E.
coli, which are the most common pathogens causing UTI in children. Another urinary tract pathology is urolithiasis.

Urolithiasis 6:00–7:19

Patients might report hematuria and severe colicky back pain radiating to the groin, while physical exam demonstrates costovertebral angle tenderness.
With these findings, consider urolithiasis and order imaging. The gold standard for diagnosing urolithiasis is a CT scan, but you can often establish the diagnosis quickly and minimize radiation exposure with an ultrasound or an X-ray of the kidneys, ureter, and bladder.
If imaging demonstrates calculi, possibly in combination with hydronephrosis on the affected side, diagnose urolithiasis.
Here’s another clinical pearl! Urolithiasis often occurs alongside urinary tract infection, so remember to order a urinalysis and urine culture as part of your diagnostic workup.
The urinalysis will often be positive for blood, white blood cells and leukocyte esterase; and the urine culture might grow more than 50,000 colony-forming units of bacteria per milliliter.
Keep in mind that a UTI in the setting of bilateral ureteral obstruction is a urological emergency that requires urgent intervention and decompression.
Now let’s discuss patients who report no urinary signs or symptoms. In this case, your next step is to assess for postprandial symptoms.

Pancreatitis 7:19–8:44

If your patient’s pain worsens after eating, assess the location of the pain. Epigastric pain should lead you to consider pancreatitis.
Affected patients often describe boring, sharp, knife-like pain with nausea and fever; and some have bilious vomiting, back pain, or abdominal distension.
Your patient might also have risk factors like trauma or systemic illness, and they might take medications associated with pancreatitis, such as valproic acid.
The exam typically reveals an ill-appearing patient with epigastric tenderness that decreases while your patient is sitting upright and worsens while they are lying down.
To confirm the diagnosis, obtain a CBC, amylase and lipase levels, and an abdominal ultrasound or CT scan. The WBCs will typically be increased, and amylase and lipase levels are often more than three times the upper limit of normal.
If imaging shows inflammation of the pancreas; possibly in combination with calculi, hemorrhage, or a pseudocyst; diagnose pancreatitis.
Another possible condition is cholecystitis. If your patient reports postprandial pain in the right upper quadrant, consider cholecystitis.

Cholecystitis 8:44–10:11

These patients typically report colicky pain radiating to the back, as well as vomiting. Some patients also have fever, and symptoms often worsen after they eat fatty foods.
History may reveal risk factors like obesity, chronic illness, or a family history of cholelithiasis. Meanwhile, physical exam classically demonstrates right upper quadrant tenderness, with a positive Murphy sign.
To elicit the Murphy sign, palpate the right subcostal region during inspiration. If your patient experiences severe sharp pain that causes them to briefly stop breathing, the Murphy sign is positive.
Lastly, some patients may also present with jaundice. To confirm the diagnosis, obtain labs, including a CBC, liver function tests, and amylase and lipase levels; and order an abdominal ultrasound.
The CBC typically reveals leukocytosis, and the serum alkaline phosphatase, direct bilirubin, amylase, and lipase levels will often be elevated.
If the ultrasound reveals gallstones, possibly with gallbladder sludge or wall thickening, diagnose cholecystitis. Now, if your patient’s symptoms improve after eating, you should consider peptic ulcer disease.

Peptic ulcer disease 10:11–11:17

Younger children might have irritability, poor feeding, vomiting, and regurgitation; while older children often have gas and bloating as well as retrosternal, chest, and abdominal pain or burning.
Your patient might report risk factors like using NSAIDs or steroids, trauma or stress, or a family history of peptic ulcer disease.
Exam findings typically include epigastric tenderness, as well as poor weight gain or weight loss. To confirm the diagnosis, perform an esophagogastroduodenoscopy, or EGD, with biopsy and culture.
The EGD will demonstrate erythema, erosions, subepithelial hemorrhage, and possibly ulcerations and muscularis mucosa defects; while the biopsy reveals inflammatory cells, and culture may grow Helicobacter pylori.
With these findings, you can diagnose peptic ulcer disease. Now let’s discuss patients whose symptoms don’t change after eating.

Ovarian cyst 11:17–12:18

In this case, you should assess the location of the pain. Pelvic pain in a post-pubertal biologically female patient should make you consider an ovarian cyst.
These patients typically report abdominal pain or unilateral pelvic pain and pressure, while the physical exam might reveal abdominal or adnexal tenderness and an adnexal mass.
Next, order a pelvic ultrasound, and if it demonstrates a cystic adnexal mass, diagnose an ovarian cyst. Here’s a high-yield fact!
Other conditions that cause acute abdominal and pelvic pain in adolescents include ovarian or testicular torsion, ruptured ovarian cysts, mittelschmerz, pelvic inflammatory disease, and ectopic pregnancy.
Lastly, let’s talk about superficial abdominal pain, which should make you consider anterior cutaneous nerve entrapment.

Anterior cutaneous nerve entrapment 12:18–13:07

The history will reveal pain along the lateral aspect of the rectus abdominis muscle that increases with sitting, twisting, or exercise, such as sit-ups.
Physical exam shows point tenderness to light touch along the lateral aspect of the rectus muscle. With these findings, diagnose anterior cutaneous nerve entrapment.
One last clinical pearl! Some systemic disorders and inflammatory conditions can also present with acute abdominal pain, including diabetic ketoacidosis, mesenteric adenitis, and Henoch-Schonlein purpura.
Alright, as a quick recap… In pediatric patients, severe acute abdominal pain with peritoneal signs indicates a surgical abdomen, which is commonly caused by appendicitis.

Review 13:07–13:40

However, in most cases, acute abdominal pain is non-surgical and is often caused by acute gastroenteritis or constipation.
Other etiologies include urinary tract infection, urolithiasis, pancreatitis, cholecystitis, peptic ulcer disease, ovarian cysts, and anterior cutaneous nerve entrapment.
Approach to acute abdominal pain (pediatrics) | Osmosis