The 14-Year-Old With Abdominal Pain and a Normal Appendix
A 14-year-old girl presents with 18 hours of central abdominal pain that has moved to the right lower quadrant. She has vomited twice and has no diarrhoea. Temperature 37.9°C, HR 104, BP 108/68. Examination: tenderness and guarding in the right iliac fossa, positive Rovsing sign, and pain on heel drop. Urine dipstick is negative for nitrites and leucocytes but shows trace ketones. She is 12 weeks into a new relationship and is sexually active; she is reluctant to discuss this in front of her mother. WCC 14.8 ×10⁹/L, CRP 32 mg/L. The surgical team is 45 minutes away and the local hospital has no on-site surgeon overnight.
1. What is your differential diagnosis and how would you handle the sensitive history?
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The presentation is classic for acute appendicitis: migratory pain, anorexia, vomiting, low-grade fever, right iliac fossa tenderness with guarding, and raised inflammatory markers. However, in a sexually active adolescent, several conditions must be considered.
Differential:
- Acute appendicitis - most likely.
- Pelvic inflammatory disease (PID) - sexually active, lower abdominal pain, possible cervical motion tenderness. Usually bilateral but can be unilateral.
- Ectopic pregnancy - must be excluded in any sexually active girl with abdominal pain, even with a negative urine dipstick (dipstick does not test for pregnancy).
- Ovarian torsion or ruptured ovarian cyst - sudden severe pain, often with vomiting.
- Urinary tract infection - dipstick negative, less likely.
- Mesenteric adenitis - possible but less likely with focal signs.
- Inflammatory bowel disease - consider if chronic symptoms, but acute presentation less likely.
Handling the sensitive history:
- Ask the mother to step out for part of the consultation, explaining that adolescents are offered confidential time. This is standard practice and improves disclosure.
- Use a non-judgemental, open approach: "Many young people your age have questions about relationships and sexual health. Is there anything you'd like to discuss privately?"
- Ask directly about sexual activity, contraception, last menstrual period, and whether there is any chance of pregnancy.
- Explain confidentiality and its limits (safeguarding concerns).
- Offer a pregnancy test (urine or serum beta-hCG) and STI screening (NAAT for chlamydia and gonorrhoea) with consent.
- Document the discussion sensitively and involve the young person in decisions about what is shared with parents.
2. The pregnancy test is negative. The surgical team advises transfer for a suspected appendicitis. What is your management plan while awaiting transfer, and what would change your mind about the diagnosis?
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Management while awaiting transfer:
- Keep the patient nil by mouth.
- Start IV fluids (0.9% saline) to maintain hydration, given vomiting and ketones.
- Give IV analgesia (e.g., morphine titrated to effect) - analgesia does not mask the diagnosis and is appropriate.
- Give IV antibiotics according to local protocol (e.g., a cephalosporin plus metronidazole) if appendicitis is suspected with perforation risk, after discussing with the surgical team.
- Monitor vital signs, pain score, and abdominal examination hourly. Record urine output.
- Arrange urgent transfer with a documented handover to the receiving surgical team, including time of last oral intake, analgesia given, and antibiotic timing.
- Do not give oral fluids or food.
What would change your mind:
- A change in pain character: sudden relief followed by generalised pain suggests perforation; worsening generalised peritonism suggests perforation or another cause.
- New findings: cervical motion tenderness or adnexal mass on examination would raise PID or ovarian pathology. A positive pregnancy test would raise ectopic pregnancy and change the pathway entirely.
- Bilious vomiting or distension would suggest obstruction.
- Diarrhoea or bloody stools might suggest gastroenteritis or inflammatory bowel disease.
- Rash or joint symptoms could suggest a systemic condition.
- Deterioration in vital signs (tachycardia, hypotension, fever) suggests sepsis or perforation and mandates immediate senior review and resuscitation.
- A negative surgical review would prompt reconsideration of medical causes, including urinary tract infection, constipation, and gynaecological causes.
Document your reasoning and discuss uncertainty openly with the patient and parents.