For many years the EmergiQuiz presentations have been one of the highlights of the AAP National Conference and Exhibition Section on Emergency Medicine Program. Pediatric Emergency Medicine Fellows present challenging cases and another fellow attempts to make the diagnosis. This is followed by an educational presentation that focuses not just on the rare diagnosis, but also the general learning inherent to the case. This post highlights a recent EmergiQuiz case.

The original EmergQuiz case submitted by Dr. Hooft, from Rady Children’s Hospital in San Diego, CA was entitled “Take me to the ER, and Step on it!”

The differential for acute abdominal pain in a child is extremely broad and requires consideration of both the unusual presentation of common causes and consideration of more rare diagnoses based on key details in the history and exam. But what do we do in cases where our routine work-up is coming back without an answer? Normal labs? Normal ultrasound(s)? Normal abdominal x-ray? Maybe even a normal CT?

It’s not always constipation

Constipation is estimated to account for close to 20% of all ED visits for abdominal pain (1,2), but beware of using this as your default diagnosis when work up is negative. Use of abdominal radiographs in the evaluation of constipation has demonstrated poor reliability in predicting fecal loading and can lead to incorrect diagnosis (3,4). Does your patient have infrequent stooling (less than 2 stools per week), difficulty stooling, hard stool, or encopresis? If the answer is no, you should probably consider other possibilities. 

Don’t forget to examine the private parts

We have all seen that kid. The teenager with cerebral palsy who presents with testicular torsion that was missed 2 days ago when he was discharged with “gastroenteritis” without a GU exam. The infant with an incarcerated hernia. What about the teen or pre-teen female who keeps coming back with abdominal pain? Hematocolopos with imperforate hymen can present this way. A basic external GU exam can drastically change your differential!

Consider the chest        

We know pneumonia and asthma are notorious for presenting with abdominal pain, so don’t be afraid to get that chest x-ray and be sure to listen closely on your lung exam. What about myocarditis? You might not see vital sign changes or abnormalities on your cardiac exam, so pay close attention for any murmurs, gallops, or rubs. Consider an EKG or even a troponin if anything peaks your suspicion, and a bedside echo is a quick and easy way to get a sense of cardiac function or evaluate for an effusion. 

What did you eat? 

Toxic ingestions such as lead poisoning or iron intoxication can present with abdominal pain, anorexia, constipation, or vomiting. Sure, in lead poisoning you may see hypochromic, microcytic anemia on the CBC, but basophilic stippling (which is pathognomonic) is not frequently seen in children. Radiopaque foreign bodies can sometimes be visualized on abdominal radiographs with large ingestions (5). Be suspicious for lead toxicity especially when other systems are affected, including neurologic, hematologic, skeletal, and renal. Iron primarily affects the liver and GI tract, but you don’t want to miss this and end up with a child in hepatic failure. 

For children who were playing (especially unsupervised) outside, toxic plants must be considered. In addition to abdominal symptoms, several plants found in North America can cause systemic symptoms, such as anticholinergic effects or CNS changes in addition to abdominal discomfort. But some plants, such as holly berries and mistletoe can cause isolated GI distress, so keep these in mind around the holidays. Amatoxin-containing mushroom toxicity can manifest with nausea, vomiting, and diarrhea, though onset can be delayed (up to 6 hours) after ingestion. Good history taking and photographic evidence of plants to which the patient may have been exposed, along with communication with the local Poison Control Center is essential to identifying these types of ingestions (6).

Bites and stings

Where does this kid live? And what do they like to play with? Snake and hymenoptera envenomations typically cause localized pain and edema, but this may not always be the case for scorpions and spiders. In smaller children, scorpion bites can cause jerking movements, fasciculations, and abnormal eye movements secondary to nervous system effects. Black widow bites may demonstrate a target lesion near the bite site, or the area may be completely painless without any markings. Patients with severe black widow envenomation, or latrodectism, may present with a chief complaint of abdominal or back pain due to muscle cramping. Be on the lookout for accompanying facial grimacing, facial edema, regional or diffuse diaphoresis, hypertension, and tachycardia (7). Black widows are pretty much everywhere, though they do typically favor warmer areas (8,9).  There are no laboratory or imaging studies that aid in specific diagnosis, so a high degree of suspicion is necessary (10–12). 

Other stuff to consider

Perhaps you won’t be the one to determine if this kid meets criteria for abdominal migraine (5+ episodes of acute abdominal pain associated with at least 2 of the following: anorexia, nausea, vomiting, or pallor), but noticing a pattern and getting them linked up with specialists for outpatient follow up may make you a hero to that family (13). What about Henoch–Schönlein Purpura (HSP)?It can present with recurrent abdominal pain prior to development of the rash or characteristic renal findings, so consider rechecking that urine sample or chemistry panel in a kid who keeps coming back with pain. Remember your HEADSS exam in teen patients. Cannabinoid hyperemesis syndrome can present with abdominal pain and persistent vomiting. Ask them about relief with a hot shower (14)! Finally, osteomyelitis and/or paraspinal or psoas abscesses can present with primary abdominal or pelvic pain, and may look relatively normal on the initial CT. Consider an MRI if your inflammatory markers are elevated and location of pain is vague…

This is by no means a comprehensive list, and we often can’t determine the exact cause of a child’s abdominal pain in one ED visit, but the goal is not to miss anything life-threatening and get them to a state where they are comfortable enough for discharge home.  Think about expanding your differential when you have a child with severe abdominal pain and your routine work up is not giving you any answers!

References

  1. Smith J, Fox SM. Pediatric Abdominal Pain: An Emergency Medicine Perspective. Emerg Med Clin North Am [Internet]. 2016;34(2):341–61. Available from: http://dx.doi.org/10.1016/j.emc.2015.12.010
  2. Caperell K, Pitetti R, Cross KP. Race and acute abdominal pain in a pediatric emergency department. Pediatrics [Internet]. 2013 Jun [cited 2014 Apr 1];131(6):1098–106. Available from: http://www.ncbi.nlm.nih.gov/pubmed/23690514
  3. Freedman SB, Thull-Freedman J, Manson D, Rowe MF, Rumantir M, Eltorki M, et al. Pediatric abdominal radiograph use, constipation, and significant misdiagnoses. J Pediatr [Internet]. 2014;164(1):83-88.e2. Available from: http://dx.doi.org/10.1016/j.jpeds.2013.08.074
  4. Petinaux B, Bhat R, Boniface K, Aristizabal J. Accuracy of radiographic readings in the emergency department. Am J Emerg Med [Internet]. 2011;29(1):18–25. Available from: http://dx.doi.org/10.1016/j.ajem.2009.07.011
  5. Dapul H, Laraque D. Lead Poisoning in Children. Adv Pediatr [Internet]. 2014;61(1):313–33. Available from: http://dx.doi.org/10.1016/j.yapd.2014.04.004
  6. Carter K, Neuspiel DR. Toxic Plants. Pediatr Rev. 2010;31(4):174–5. 
  7. Bond GR. Snake, spider, and scorpion envenomation in North America. Pediatr Rev. 1999;20(5). 
  8. Vetter R. Widow Spiders and their Relatives. Pest Notes, UC Integr Pest Manag [Internet]. 2017;74149:1–8. Available from: http://ipm.ucanr.edu/PDF/PESTNOTES/pnblackwidow.pdf
  9. Isbister GK, Fan HW. Spider bite. Lancet. 2011;378(9808):2039–47. 
  10. Clark RF, Wethern-Kestner S, Vance M V., Gerkin R. Clinical presentation and treatment of black widow spider envenomation: A review of 163 cases. Ann Emerg Med. 1992;21(7):782–7. 
  11. Reeves JA, Allison EJ, Goodman PE. Black widow spider bite in a child. Am J Emerg Med. 1996;14(5):469–71. 
  12. Woestman R, Perkin R, Van Stralen D. The black widow: is she deadly to children? Pediatr Emerg Care. 1996;12(5):360–4. 
  13. Napthali K, Koloski N, Talley NJ. Abdominal migraine. Cephalalgia [Internet]. 2016;36(10):980–6. Available from: http://dx.doi.org/10.1016/j.spen.2015.09.001
  14. Miller JB, Walsh M, Patel P, Rogan M, Arnold C, Maloney M, et al. Pediatric Cannabinoid Hyperemesis: Two Cases. 2010;26(12):919–20.