A Med-peds Approach to Acute Abdominal Pain in Pediatric Lupus

Introduction: Systemic lupus erythematosus (SLE) is rare in children. Conversely, acute abdominal pain (AAP) is a common presenting symptom in pediatrics. It is estimated that at least 50% of SLE patients develop gastrointestinal symptoms, including abdominal pain, after diagnosis. We present a 9-year-old with SLE with AAP after initiation of SLE treatment.

Case Description: An obese, Hispanic 9-year-old girl presented to the Emergency Department (ED) with syncope, emesis, and scleral icterus. Notable testing is at the top of Figure 1. Patient was diagnosed with autoimmune hemolytic anemia (AIHA). She improved with blood transfusions and corticosteroids. Review of systems was positive for oral ulcers. Additional serologies are listed at the bottom of Figure 1. Meeting the American College of Rheumatology criteria, she was diagnosed with SLE.

Hydroxychloroquine, azathioprine, and corticosteroids were prescribed. One month after, she presented to the ED with post-prandial AAP. She was diagnosed with dyspepsia and prescribed antacids with pain resolution. One week later, she re-presented to the ED with AAP. Notable testing is in Figure 2. Ultrasound revealed common bile duct dilation, MRCP demonstrated choledocholithiasis, and ERCP showed isolated cholelithiasis. Stone pathology was not performed. Patient underwent laparoscopic cholecystectomy for definitive management.

Discussion: Pediatric SLE (pSLE) patients with AAP are most often diagnosed with gastroenteritis, appendicitis, pancreatitis, and cholecystitis. The latter are diagnoses far more prevalent in the general adult population than pediatrics. However, their inclusion is critical in the pSLE population.

Examining the AAP differential for our patient, overlapping gastrointestinal side effects of hydroxychloroquine and azathioprine include abdominal pain, diarrhea, nausea, and emesis. Azathioprine can also cause pancreatitis and hepatitis. Corticosteroid use correlates with pancreatitis, gastritis, and peptic ulcers.

AIHA is 3x more common in pSLE than adult. This patient’s history of AIHA predisposes her to pigment cholelithiasis due to increased bilirubin excretion from hemolysis. Additionally, she had risk factors contributing to non-pigmented cholelithiasis including female gender, Hispanic ethnicity, and BMI % >2SD scores.

Lupus enteritis presents with diffuse abdominal pain in patients with active SLE. On CT, bowel wall thickening, mesenteric edema, enlarged mesenteric vasculature, and ascites are present. Acalculous cholecystitis due to SLE-induced vasculitis and thrombi secondary to antiphospholipid antibodies should also be considered. Serositis, thrombosis, and mesenteric vasculitis can also present as AAP in SLE patients.

Conclusion: AAP is a common pediatric complaint. The differential for a pSLE patient with AAP must be broad and include diagnoses more commonly seen in adults, in addition to those in general pediatrics. Medication side effects, complications from diagnoses like AIHA, and SLE-related gastrointestinal manifestations should also be considered. Pigmented or non-pigmented cholelithiasis can be the culprit of AAP in pSLE patients. As seen with this patient, demographics and lupus-related factors can increase likelihood of a diagnosis more commonly seen in adults.