Generalised peritonitis or sepsis: resuscitate (Sepsis Six if septic) and get an emergency surgical review. Do not delay antibiotics if perforation is suspected.
Typical features
- Periumbilical pain migrating to the right iliac fossa
- Anorexia, nausea, low-grade fever
- Rovsing, psoas and obturator signs, guarding
- Rebound and percussion tenderness suggest peritonism
Differentials to exclude
- Gynae: ectopic (do a pregnancy test), ovarian torsion, PID
- Urinary: ureteric stone, UTI
- Mesenteric adenitis, Meckel diverticulum, Crohn flare
- Right-sided diverticulitis, caecal pathology in older patients
Early / uncomplicated
- Localised RIF pain
- Stable observations
- Analgesia, appendicectomy
Diagnostic uncertainty
- Alvarado score or imaging (US or CT)
- Pregnancy: US or MRI, avoid CT
- Serial examination, surgical review
Perforation / sepsis
- Generalised peritonitis, shock
- Sepsis Six, IV antibiotics
- Urgent surgery and resuscitation
Management
1
1. Assess and score
Alvarado or AIR score, observations, urinalysis, and a pregnancy test in women of child-bearing age.
Alvarado or AIR score, observations, urinalysis, and a pregnancy test in women of child-bearing age.
↓
2
2. Investigate
FBC, CRP, U&E. Imaging if the diagnosis is unclear: USS first in children and women, CT in adults (especially over 40, to exclude other causes).
FBC, CRP, U&E. Imaging if the diagnosis is unclear: USS first in children and women, CT in adults (especially over 40, to exclude other causes).
↓
3
3. Resuscitate and treat
Nil by mouth, IV fluids, analgesia and antiemetic. IV antibiotics if perforation or sepsis; prophylactic antibiotics before surgery.
Nil by mouth, IV fluids, analgesia and antiemetic. IV antibiotics if perforation or sepsis; prophylactic antibiotics before surgery.
↓
4
4. Refer and operate
Laparoscopic appendicectomy when confirmed or strongly suspected. Non-operative antibiotic management only in selected cases after discussion.
Laparoscopic appendicectomy when confirmed or strongly suspected. Non-operative antibiotic management only in selected cases after discussion.
| Feature | Points |
|---|---|
| Migration of pain to RIF | 1 |
| Anorexia | 1 |
| Nausea or vomiting | 1 |
| Tenderness in RIF | 2 |
| Rebound tenderness | 1 |
| Elevated temperature | 1 |
| Leukocytosis | 2 |
| Left shift of neutrophils | 1 |
Special groups
- Pregnancy: pain may be higher; USS or MRI preferred
- Children and older adults present atypically
- Immunosuppressed may lack classic signs
Pitfalls
- Analgesia does not mask a surgical abdomen: give it
- Missing ectopic or torsion in women
- A normal CRP early does not exclude appendicitis
- Delaying theatre in a perforated or septic patient
MedPrep - www.medprep.uk - Educational revision aid only. Not clinical guidance. Doses are adult examples; check the BNF, current guidelines and local policy, and seek senior advice. Nov 2026