Acute abdominal pain in children: Case

This adolescent girl has acute right lower quadrant pain that must be assumed to have a time-critical cause until proven otherwise, and the leading diagnoses are appendicitis and ovarian torsion, with ectopic pregnancy held as a must-not-miss given her missed period. The sudden onset overnight, the severity, the pallor and clamminess, and the exquisite right iliac fossa tenderness all argue for an urgent workup rather than observation alone, and a pregnancy test is the first bedside step. [1]

Clinical findings

The findings that demand urgency are the sudden severe onset, the pallor and clamminess, the tachycardia, and the exquisite localised tenderness with voluntary guarding in the right iliac fossa. Sudden, severe, constant unilateral lower abdominal pain with nausea and vomiting is the hallmark of ovarian torsion, in which the ovary twists on its vascular pedicle and becomes ischaemic within hours. The absence of fever and the normal temperature do not exclude a surgical cause. [1]

The candidate must build the differential around the surgical threats. Appendicitis remains the most common surgical cause in this age group and can present with sudden right iliac fossa pain, though the migration from a periumbilical ache is its signature and is absent here. Ectopic pregnancy must be excluded with a pregnancy test in any adolescent girl with acute abdominal pain, and a ruptured ovarian cyst and pelvic inflammatory disease are added. The candidate should state plainly that ovarian torsion and ectopic pregnancy cannot be excluded clinically and demand investigation without delay. [1]

Investigations

The first investigation is a urinary or serum pregnancy test, and it is performed before any imaging, because ectopic pregnancy is a life-threatening diagnosis and its identification changes the entire pathway. Once pregnancy is excluded, pelvic ultrasound with Doppler is the investigation of choice for suspected ovarian torsion, looking for an enlarged ovary and altered or absent blood flow. [1]

The critical point is that a normal or equivocal Doppler ultrasound does not exclude ovarian torsion, because venous and lymphatic obstruction precede arterial occlusion, and intermittent torsion can produce normal flow. A high clinical suspicion therefore prompts urgent gynaecological assessment and diagnostic laparoscopy rather than reassurance from a normal scan. Bloods include a full blood count, a group and hold, and a venous gas if she is shocked, and an abdominal ultrasound can assess the appendix in parallel. [1]

Management

Management begins in parallel. The candidate keeps her nil by mouth, secures intravenous access, gives early titrated analgesia, sends bloods including a group and hold, and requests the pregnancy test and the pelvic ultrasound with Doppler. Early analgesia is given without hesitation, because opioid analgesia relieves pain in children with acute abdominal pain without reducing the accuracy of examination or the rate of correct diagnosis. [3]

The definitive treatment depends on the diagnosis. For ovarian torsion it is urgent laparoscopy with detorsion and ovarian conservation wherever the ovary is viable, and the speed matters because the ovary becomes non-viable within hours. For appendicitis it is prompt appendicectomy, which the 2025 World Society of Emergency Surgery guidelines reaffirm as the reference standard, with antibiotics for complicated disease. For a ruptured ectopic pregnancy it is urgent surgery. The candidate should make clear that the time-critical possibilities dominate and that the surgeon or gynaecologist is involved immediately. [2]

Disposition and safety-netting

This girl is admitted rather than discharged, because she has acute severe pain with signs that demand a surgical or gynaecological diagnosis and because ovarian torsion and ectopic pregnancy cannot be excluded clinically. The candidate should state the admission criteria for any child with acute abdominal pain: a clear or suspected surgical diagnosis, peritonitis or shock, an equivocal presentation needing observation, and any inability of the family to return safely. [2]

The safety-net is the key communication skill and is given to every family, including those admitted. The candidate should tell the family in plain language that the pain is being taken seriously, that ovarian torsion and appendicitis are being actively excluded, and that she must not eat or drink while assessment continues. If any child is discharged with a medical diagnosis, the family returns immediately if the pain worsens, localises or becomes constant, if the vomit turns green or bloody, if the child becomes drowsy or feverish, or if she cannot keep fluids down. Asking the family to repeat the warning signs confirms understanding. [2]