History and exam

Key diagnostic factors

common

abdominal pain

Abdominal pain is the main presenting symptom.

  • Typically starts as central abdominal pain, and 1 to 12 hours later it moves to the right lower quadrant as the inflammation progresses.[24] Remember that the location of the appendix varies, and consequently so does the location of the pain.[25]

  • Usually constant with intermittent cramps.[24]

  • Often worse on movement and coughing.[24]

Remember that the location of the pain can vary depending on the position of the appendix:[25]

  • A retrocaecal appendix can cause flank or back pain

  • A retroileal appendix can cause testicular pain due to irritation of the spermatic artery or ureter

  • A pelvic appendix can cause suprapubic pain

  • A paracolic long appendix with tip inflammation in the right upper quadrant may cause pain in this region.

anorexia

Almost always present.[12]

  • If the patient is hungry and wants to eat, this is reassuring and makes appendicitis less likely.[25]

nausea and vomiting

Present in 75% of patients.[12]

  • Significantly associated with appendicitis in pregnant patients.[34]

  • Vomiting may also occur in late appendicitis if there is small bowel obstruction due to an appendiceal abscess.[33]​​

right lower quadrant tenderness

A common sign of appendicitis.[25]

  • However, in pregnant women, atypical pain such as right upper quadrant or right flank pain may occur after the first trimester due to displacement of the appendix by the gravid uterus.[29]

  • Localised peritonitis with guarding may be a sign of a perforated appendix and is also strongly associated with appendicitis in pregnant patients.[34]

high’ or ‘intermediate’ risk score

Use a scoring system in adults to determine the likelihood or rule out the diagnosis of appendicitis in order to guide further investigations and management.[7]

  • Use either the Appendicitis Inflammatory Response (AIR) or the Adult Appendicitis Score (AAS) to determine whether your patient is at high, intermediate, or low risk of having appendicitis.[7]

    • High-risk patients who are aged <40 years, and have strong symptoms and signs of appendicitis, may go straight to surgery without imaging.[7] However, check your local protocols as this varies in practice.

    • Intermediate-risk patients may undergo further imaging and observation.[7]

    • Low-risk patients may be safely discharged without diagnostic imaging, as long as they have appropriate safety-netting.[7]

  • The Alvarado score can be used to rule out appendicitis but do not use it to positively confirm a diagnosis of appendicitis; it is not specific enough for that purpose.[7]

  • All the scoring systems involve a combination of history, examination findings, and investigation results.[7]

  • Evidence for the use of scoring systems, such as the Alvarado score, in elderly patients is limited, and they should not be used to replace cross-sectional imaging to make a diagnosis of appendicitis in this patient group.[4][5]

In children, do not make the diagnosis of appendicitis based on clinical scores alone.[7] Children frequently have atypical clinical features and obtaining a reliable history can be challenging. Clinical scores are useful tools in excluding acute appendicitis in children. The diagnosis of acute appendicitis in children should be made on the basis of clinical suspicion, blood tests, and, if needed, imaging (see the Investigations section).

Use the following table to calculate the score for your patient, depending on which scoring system you are using:[40][41]

AIR[40]

AAS[41]

Alvarado*[40][42]

PAS*[43]

History

Vomiting

1 point

N/A

1 point for either vomiting OR nausea

1 point for either vomiting OR nausea

Anorexia

N/A

N/A

1 point

1 point

Pain in right lower quadrant

1 point

2 points

2 points

N/A

Migration of pain to the right lower quadrant

N/A

2 points

1 point

1 point

Examination

Right lower quadrant tenderness

N/A

  • Women aged 16-49: 1 point

  • Women aged ≥50 and men: 3 points

N/A

2 points for right lower quadrant tenderness to cough, percussion, or hopping

Right iliac fossa tenderness

N/A

N/A

N/A

2 points

Rebound tenderness or guarding

  • Light: 1 point

  • Medium: 2 points

  • Strong: 3 points

  • Mild: 2 points

  • Moderate or severe: 4 points

1 point

N/A

Fever

>38.5℃: 1 point

N/A

>37.3℃: 1 point

>38.0℃: 1 point

Blood test results

Leukocytosis shift

N/A

N/A

1 point

N/A

Proportion of neutrophils

  • <70: 0 points

  • 70-84: 1 point

  • ≥85: 2 points

  • <62: 0 points

  • ≥62 and <75: 2 points

  • ≥75 and <83: 3 points

  • ≥83: 4 points

N/A

N/A

Absolute neutrophil count

N/A

N/A

N/A

>7500: 1 point

White blood cell count (× 10 9/L)

  • <10.0: 0 points

  • 10.0–14.9: 1 point

  • ≥15.0: 2 points

  • <7.2: 0 points

  • ≥7.2 and <10.9: 1 point

  • ≥10.9 and <14.0: 2 points

  • ≥14.0: 3 points

  • ≤10: 0 points

  • >10: 2 points

  • >10: 1 point

C-reactive protein (mg/L)

  • <10: 0 points

  • 10–49: 1 point

  • ≥50: 2 points

Symptoms <24 hours

  • <4: 0 points

  • ≥4 and <11: 2 points

  • ≥11 and <25: 3 points

  • ≥25 and <83: 5 points

  • ≥83: 1 point

Symptoms >24 hours

  • <12: 0 points

  • ≥12 and <152: 2 points

  • ≥152: 1 point

N/A

N/A

Add up the total number of points for your patient to calculate the risk of appendicitis as follows:[40][41]

High risk

  • AIR: 9-12 points

  • AAS: ≥16 points

  • Alvarado: 9-10 points

  • PAS: ≥7 points

Intermediate risk

  • AIR: 5-8 points

  • AAS: 11-15 points

  • Alvarado: 5-8 points

  • PAS: 4-6 points

Low risk

  • AIR: 0-4 points

  • AAS: 0-10 points

  • Alvarado: 0-4 points

  • PAS: <4 points

*In children, do not make the diagnosis of appendicitis based on clinical scores alone.[7] Children frequently have atypical clinical features and obtaining a reliable history can be challenging. Clinical scores are useful tools in excluding acute appendicitis in children.[7]

uncommon

tense, rigid abdomen

A sign of generalised peritonitis that indicates a perforated appendix.[25]

hypotension and tachycardia

Signs of shock or sepsis that indicate a perforated appendix.[2]​​

palpable mass

Due to a peri-appendiceal abscess caused by a perforation that is contained by the omentum.[7]

Other diagnostic factors

common

age of occurrence

Most commonly occurs between the ages of 10 and 30 years, with the highest incidence in children and adolescence.[7][13]

low-grade pyrexia

Temperature >37.8°C (>100.1°F).[2][25]​​​

  • Consider other causes if there is a very high fever.

flushed face and a fetor

May be present in both complicated and uncomplicated appendicitis.[29]

reduced bowel sounds

A sign of perforated appendicitis.[25]

tachycardia

Tachycardia may be present, particularly in patients with perforation.[29]

uncommon

loose stool

The patient may pass small volumes of mucus from the rectum if there is a pelvic appendicitis with a collection. The patient may describe this mucus as ‘diarrhoea’ (whereas stool volume is increased in true diarrhoeal illness).[12]

constipation

Sometimes present in appendicitis.[29]

flexed right hip (psoas sign)

Present in retrocaecal appendicitis.[12]

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