Acute Appendicitis: Recognising the Pattern and Knowing When to Refer
A community pharmacy triage guide to recognising acute appendicitis, including the classic pain migration pattern, atypical presentations, key differentials, and when to call 999.
Why this matters
Appendicitis is inflammation of the appendix, usually caused by obstruction of its lumen and often associated with secondary infection. A small pouch attached to the large bowel in the lower right abdomen, the appendix is one of the most common sources of surgical emergency in all age groups. It can occur at any age, but is most common in older children, teenagers, and young adults.
Community pharmacists are often the first person consulted by someone with abdominal pain who is unsure whether to seek further help. The condition typically develops over 12 to 48 hours and is easy to dismiss early on: the pain begins mildly and centrally, often around the belly button, and may be attributed to indigestion, trapped wind, or a stomach upset. As hours pass, the pain migrates to the lower right abdomen and worsens steadily. Without surgical assessment, the appendix can rupture, leading to peritonitis (infection of the abdominal lining) and, in the worst cases, sepsis. The pharmacist's role is not to diagnose appendicitis. It is to recognise when the pattern of pain warrants urgent escalation.
Several conditions cause similar symptoms and are relevant to the referral decision: gastroenteritis (vomiting typically starts before or alongside pain, loose stools, no migration), urinary tract infection (burning on urination, frequency, flank pain), renal colic (severe loin-to-groin pain, often colicky), ectopic pregnancy (right lower abdominal pain in any woman of childbearing age: a surgical emergency to consider alongside appendicitis), ovarian cyst rupture or torsion, pelvic inflammatory disease, mesenteric adenitis in children (similar presentation to appendicitis, often follows a recent respiratory illness), and constipation (commonly confused with appendicitis, particularly in children: pain is usually colicky, there is no migration, and bowel habit confirms the pattern). In boys and young men, testicular torsion can present with lower abdominal pain and is also a surgical emergency. The key pharmacy point is that most of these also require same-day medical assessment. The referral decision is the same regardless of which diagnosis is ultimately confirmed.
Suspected appendicitis should not be managed with self-care alone. There is no medication and no period of watchful waiting that replaces urgent hospital assessment when the clinical picture is concerning.
Red flags vs more likely benign
| Feature | More likely benign | Red flag ⚠ |
|---|---|---|
| Pain progression | Pain stable, improving, or coming and going (colicky) | Pain worsening steadily over hours and migrating from around the belly button to the lower right abdomen: this progression is one of the most characteristic features of appendicitis |
| Effect of movement | Pain unchanged by movement or walking | Pain clearly worsened by walking, coughing, or travelling over bumps: the patient may walk slowly, hunched forward, or hold their abdomen |
| Appetite | Mildly reduced or unaffected | Marked loss of appetite, including refusal of favourite food: anorexia is commonly present in appendicitis and is an early, consistent feature |
| Nausea and vomiting | Vomiting that starts before or alongside the abdominal pain: more consistent with gastroenteritis | Nausea or vomiting that follows the onset of abdominal pain: in appendicitis, pain leads and vomiting follows |
| Temperature | Afebrile throughout with no other concerning features | Temperature at or above 38 degrees Celsius alongside worsening abdominal pain: supportive of appendicitis, but absence of fever does not exclude it, particularly in older adults, immunocompromised patients, or early disease |
| Bowel habit | Normal bowel habit throughout | Bowel habit changes are unreliable in appendicitis: diarrhoea does not exclude appendicitis, particularly in children or with pelvic appendicitis. Do not use diarrhoea to favour gastroenteritis over appendicitis. |
| Sudden pain change | Pain gradually and consistently easing | Brief apparent improvement in pain followed by severe pain spreading across the whole abdomen: the appendix may have ruptured. Call 999. |
| General condition | Alert, comfortable at rest, able to walk and hold a normal conversation | Pale, sweating, visibly unwell, or reporting a rapid heartbeat: signs of deterioration, peritonitis, or sepsis requiring 999 immediately |
Think Appendicitis if Your Patient Says...
The pain migration story is one of the most useful clues the pharmacist can gather. These phrases should prompt immediate referral.
- "It started near my belly button a few hours ago and now it is low down on the right."
- "The pain keeps getting worse, not better."
- "Every bump in the car on the way here hurt."
- "Walking makes it worse."
- "I do not want to eat anything, not even things I normally like."
- "I was sick, but the pain started before I was sick."
The combination of migrating pain, complete anorexia, and vomiting that follows pain onset is highly suggestive of appendicitis and warrants urgent same-day assessment.
🛑 SHARP: A Quick Assessment Framework
Use this prompt at the counter when any patient presents with abdominal pain that could be appendicitis.
Ask where the pain first appeared. Periumbilical onset that has since moved to the lower right abdomen over hours is the most useful single feature of appendicitis.
Is the patient walking slowly, bent forward, or holding their abdomen? Involuntary guarding on movement strongly suggests peritoneal irritation.
Has appetite disappeared completely, even for favourite food? Anorexia is commonly present in appendicitis and is one of the earliest consistent features.
Is pain worse on walking, coughing, or going over a bump? This pattern of movement-worsened pain suggests peritoneal irritation and warrants same-day assessment.
Always consider ectopic pregnancy in women of childbearing age with right lower abdominal pain. An ectopic pregnancy is a surgical emergency and must be considered alongside appendicitis.
Atypical Presentations: Who May Not Fit the Classic Picture
In several groups, appendicitis does not follow the classic pattern. A lower threshold for referral applies to all of them.
- Older adults: fever may be absent or very low-grade, pain may be less severe or poorly localised, and confusion can dominate. Older adults frequently present late and have perforation rates reported as high as 70% in some studies.
- Young children, particularly under five years: the classic pain migration is less reliably present. Vomiting, diffuse abdominal pain, loose stools, irritability, and difficulty walking are common. Children deteriorate faster once the appendix perforates.
- Pregnant patients: as the pregnancy progresses, the appendix is displaced upward. Pain may be felt in the right upper or mid-abdomen rather than the right lower abdomen. Malaise, heartburn, and pelvic pain may dominate the picture.
- Women of childbearing age: ectopic pregnancy, ovarian cyst rupture or torsion, and pelvic inflammatory disease all cause right lower abdominal pain. Ectopic pregnancy is a life-threatening emergency. Always consider it alongside appendicitis in this group.
- Immunocompromised patients (for example those on long-term corticosteroids, chemotherapy, or immunosuppressants after transplant): fever and localising signs may be absent or blunted. A lower threshold for referral applies regardless of how well the patient appears.
- Boys and young men: testicular torsion can present with lower abdominal pain and may be difficult to distinguish from appendicitis at the counter. Both are surgical emergencies. Ask about scrotal pain or swelling in any adolescent boy or young man with lower abdominal pain, and refer urgently either way.
A parent saying their child is just not right, is not eating, and is walking oddly warrants the same urgency as a textbook adult presentation. Do not require the classic pattern before referring.
What to do in pharmacy
Key takeaways
- Pain that starts around the belly button and migrates to the lower right abdomen over hours, with marked loss of appetite, is highly suggestive of appendicitis and warrants same-day assessment without delay.
- A sudden improvement in abdominal pain followed by severe widespread pain means the appendix may have ruptured: call 999 immediately.
- In women of childbearing age, right lower abdominal pain needs urgent assessment to exclude ectopic pregnancy alongside appendicitis: both are surgical emergencies.