Diagnosis of Appendicitis
How To Know If You Have Appendicitis

The diagnosis of appendicitis is not always straight forward from the signs and symptoms. The following are common lab tests, scans and scoring systems used in the diagnosis of acute appendicitis. See if you can use some of the information here to help tell if you are having appendicitis. Leave us some comments.

The Diagnosis of AppendicitisThe Diagnosis of appendicitis could be very challenging even to the most experienced surgeon sometimes.

The diagnosis of acute appendicitis is mainly based on the story (history) given by the patient and the findings on physical examination.

In many situations, the signs and symptoms of this condition does not follow the usual pattern. Even if it does, it is often necessary to have some other supportive and reproducible ways of establishing the diagnosis.

This is why scoring systems, laboratory testings, scans and other other procedures have been devised to help in making sure that it is indeed a case of acute appendicitis that is being dealt with.

The "usual" symptoms of acute appendicitis are:

  • Abdominal pain - this pain could start from the upper central abdomen, or even around the navel or umbilicus and after a few hours or days, it moves to the lower right abdomen.
  • Associated fever in some cases
  • Loss of appetite and nausea
  • Constipation, though in children it could be more of diarrhea
  • Vomiting once or twice long after the commencement of the pain
  • Pain worsens on movement or coughing or riding in a car

In children less than 2 years old and the elderly over 80 years of age, appendicitis could present in a less obvious manner. Other people at risk from difficulty with prompt diagnosis of this condition are pregnant women.

So, how can you tell you have appendicitis? The following are the tools used in the diagnosis of acute appendicitis.

Blood Tests For Appendicitis

Remember that ...

  • The Diagnosis of acute appendicitis is still largely based on the history and physical examination of the patient
  • In many cases, it is unnecessary to do any further testing or scanning
  • In infants, children, those who are 65 years or older and pregnant women, there may be a need for specialized testing as diagnosis is often more of a challenge in this group
  • An Ultrasound scan may be necessary in any women of childbearing age who presents with symptoms of acute appendicitis to exclude ovarian pathology, if such is suspected
  • CT scan is the best diagnostic tool in those over 65 years of age and if an appendix mass or abscess is suspected. 

There is no single blood test that can be done (at least for now), to make a diagnosis of appendicitis. Most patients suspected of having appendicitis would be asked to do a blood test. These tests are done to help support the presence of infection. Such infection is not specific for appendicitis. 50% of the times, the blood test may be normal. So it is not fool proof in helping to determine presence of an infection.

Two types of blood test commonly done to point to the presence of infection are:

  • FBC (Full blood count) or CBC (Complete blood count), is an inexpensive and commonly requested blood test. It involves the measurement of the blood for the level or amount of red blood cells as well as the number of the various white blood cell constituents in it. The number of white cells in the blood is a usually less than 10,000cells per cubic millimetre. An abnormal rise in the number of white blood cells in the blood is a crude indicator of infection or inflammation going on in the body. Such rise is not specific to appendicitis alone. If it is abnormally elevated, with a good history and examination findings pointing towards appendicitis, the likelihood of having the disease is higher. In pregnancy, there may be a normal elevation of white blood cells, without any infection present.

  • CRP is an acronym for Cryo-Reactive Proteins. It is an acute phase response protein produced by the liver in response to any infection or inflammatory process in the body. Again, like the FBC, it is not a specific test. It is another crude marker of infection or inflammation. Inflammation at ANY site can lead to the CRP to rise. A significant rise in CRP with corresponding signs and symptoms of appendicitis is a useful indicator in the diagnosis of appendicitis. It is said that if CRP continues to be normal after 72 hours of the onset of pain, it is likely that the appendicitis will resolve on its own without intervention. A worsening CRP with good history is a sure signal fire of impending perforation or rupture and abscess formation.

Urine Test In The Diagnosis of Appendicitis?

Actually, urine testing is a normal component in the work up to the diagnosis of acute appendicitis. While in most cases a urine test in appendicitis would come back with a normal result, there are times when there would be blood in the urine with appendicitis.

Such blood in the urine results if the inflamed appendix is rubbing on the wall of the bladder, causing local inflammation of the bladder. Such patient may also witness an increased frequency in urinating. It does not necessarily mean that the patient is having a UTI.

It is also important to do a urine test when investigating the possibility of acute appendicitis so as to be able to exclude the presence of concurrent pregnancy or perhaps establish if an acute bladder or kidney infection is what might be causing the symptoms of appendicitis.

Appendicitis Scoring Systems

In the diagnosis of appendicitis, some physicians have come up with scoring systems, which compiles all the clinical signs and symptoms a patient could have, gives it a mathematical number, and if the score reaches a particular total or threshold, a diagnosis of appendicitis is said to be very likely. These scoring systems have also been referred to as appendicitis algorithms.

Scoring systems are not frequently used in clinical settings but could be a great tool for the curious reader, medical student or budding doctor to help determine the probability of the constellation of symptoms described by a patient as being due to acute appendicitis. 

The following are the available scoring systems in the diagnosis of acute appendicitis.

1. MANTRELS or Alvarado Scoring.

The Alvarado scoring system in appendicitis, also called the MANTRELS scoring, makes use of clinical signs, symptoms and laboratory findings. Each of the alphabets represents a sign or symptom, and a score of 1 is award to each, where they exist, except T and S that are scored 2 each. The components are as follows:

M = Movement of pain to the right iliac fossa

A= Anorexia

N = Nausea and Vomiting

T = Tenderness in the right iliac fossa

R = Rebound tenderness

E= Elevated temperature …and …

L = Leucocytosis greater than 10,000/mm2

S = Shift in white blood cell count to the right.

A total score of 10 is the maximum that can be accumulated.

A score of 8 – 10 is said to be highly predictive of appendicitis and is a call for immediate appendectomy or operation for the removal of the appendix.

A score of 7 – 8 is indicative of appendicitis. 5 – 6 means there is the possibility of appendicitis, and 1 – 4 makes the diagnosis of appendicitis unlikely.

Any one scoring 5 – 8 needs regular clinical re-evaluation and re-assessment with a view to confirming the diagnosis and operate.

A score of greater than 6 in children makes the possibility of appendicitis up to 100% likely.

2. Pediatric Appendicitis Scoring

The Paediatric Appendicitis Scoring abbreviated PAS Scoring in children is another predictive scoring system used in the diagnosis of appendicitis.

This scoring system is designed for use in children between the ages of 4 – 15 years. It is more or less a modified Alvarado or MANTRELS scoring. It uses 8 variables (laboratory findings as well as sighs and symptoms), to which a score is of 1 or 2 is given to each variable, where they exist. The maximum score that can be accumulated is 10.

The presence of Anorexia, Pyrexia, Nausea or Vomiting, Leucoystosis greater than 10,000, migration of pain, and high neutrophils are given a score of 1 each. Tenderness on coughing, hopping or percussing the abdomen is given a score of 2. So too is the presence of tenderness in the right lower abdominal region. A Paediatric Appendicitis Score of 6 and above is highly indicative of appendicitis in children.

Tzanakis Scoring

Tzanakis and colleagues, in 2005 published a simplified system, now called the Tzanakis scoring system for appendicitis, to aid in the diagnosis of appendicitis.

It incorporates the presence 4 variables made up of specific signs and symptoms:

  • Presence of right lower abdominal tenderness = 4 points and rebound tenderness = 3,
  • Laboratory findings (presence of white blood cells greater than 12,000 in the blood = 2) as well as
  • Ultrasound findings (presence of positive ultrasound scan findings of appendicitis = 6).

A total score of 15 is the maximum that can be scored. Where a patient scores 8 or more points, there is greater than 96 percent chance that appendicitis exists.

Abdominal X-Ray In Appendicitis

In some parts of the world, abdominal x-ray is still included in the work up towards the diagnosis of appendicitis.

This could be in the form of plain abdominal radiography or in association with the use of a barium meal.

  • In 10% of patients with appendicitis, plain abdominal x-ray may demonstrate hard formed feces compacted together with calcium phosphate salt and bacteria, in the lumen of the appendix (Faecolith).
  • The finding of faecolith in the appendix on x – ray alone is usually a reason to operate to remove the appendix, because of the potential to cause worsening symptoms.
  • An abdominal x – ray may be done with a barium enema contrast to diagnose appendicitis.
  • Barium enema is whitish toothpaste-like material that is passed up into the rectum to act as a contrast. It fills the whole of the large bowel. In a normal appendix, the lumen will be present and the barium fills it up and this is clearly seen when the x-ray film is taken and viewed.
  • In acute appendicitis, the lumen is obliterated due to swelling and inflammation and would not be seen in the barium enema film.

Ultrasound Scan

Ultrasound scan is frequently requested in women of child bearing age and the pregnant woman, when ovarian cyst or inflamed tubes are suspected to be the probable cause of their symptoms.

The normal appendix is not frequently visible on ultrasound scan. If seen, it is most likely that the appendix is inflamed. What the ultrasound would be looking for include:

  • Swollen or dilated tube-like shadow attached to or near the cecum
  • Presence of fecoliths in teh appendix
  • Thick-walled. An outer wall thickness of greater than 7mm on scanning is highly suggestive of inflammation of the appendix.
  • Free-fluid surrounding this structure.

Graded Compression Ultrasound greatly improves the sensitivity of ultrasound scan in the diagnosis of appendicitis in all age groups and sex.

Graded Compression Ultrasound has been demonstrated to have a sensitivity of 100% and specificity of 96 % and accuracy of 98% in the diagnosis of appendicitis during pregnancy


CT Scan

Studies have shown that females are more likely to be wrongly diagnosed as having acute appendicitis, compared to males. It is therefore increasingly important that where possible, a CT scan should be done to support the diagnosis of appendicitis in a woman, especially if there is some doubt about the diagnosis. 

If an ovarian disease is suspected, ultrasound scan is advised instead.

Current guidelines dictate that in older patients - 65 years of age and older, or where the diagnosis is in doubt, a CT scan of the appendix (abdominal CT scan), should be done to aid the diagnosis of acute inflammation of the appendix.

CT scan called computed tomography scan in full, is a specialized form of x-ray. The patient is passed through a big doughnut-like machine and x-rays 400 times the normal is used to look at the body in slices of about 5 millimeter thickness.

It is used in a very wide selection of medical cases. It is not advised to be used in pregnancy, except where the benefit strongly out weighs the risk.

A dye may be given to help improve the visibility of tissues, by acting as a contrast.

Helical CT scan has greatly improved the diagnosis of appendicitis. It is rapidly becoming the only diagnostic tool with some certainty.

Types of CT done include:

  • Standard abdominal and pelvic CT with dye injected through the vein, or where patient cannot tolerate an intravenous dye, a dye through the mouth should be given
  • CT scan that zooms down on the appendix with dye given through the rectum or back passage
  • Normal Ct scan without a contrast.

Features on abdominal CT scan that points to the diagnosis of appendicitis are infect similar to those expected or seen on ultrasound, except that they would be in a higher resolution. They include:

  • Swollen appendix with a diameter greater than 6 mm and no visible lumen (blocked)
  • Thickening of the wall of the appendix, greater than 3 mm
  • Fecolith in the appendix.

Fine Catheter Peritoneal Cytology

This is a rather old fashioned test for appendicitis. It is in fact hardly used today for the diagnosis of appendicitis.

Abbreviated FCPC, fine catheter peritoneal cytology when used, has a high predictive value for diagnosing appendicitis.

It involves the introduction of a fine catheter into the abdominal cavity below the level of the umbilicus or navel, and then the catheter is directed to the right iliac fossa and peritoneal fluid aspirated, and stained in the lab with Giemsa stain.

If over half of the cells in the aspirate are white blood cells (neutrophils), the test is said to be positive, and appendicitis is most likely.

The draw back of this test is in women where a positive test can also occur with a pelvic inflammatory disease.


Published on the 30th of June 2005 by Abdopain.com Editorial Team under causes of lower right sided abdominal pain.
Article was last reviewed on 12th October 2015.

Appendicitis Stories - Have Your Say!

Are you suffering with a right sided abdominal pain? Do you suspect that this might be due to appendicitis? Or have you had your appendix removed? What was your experience like? Share your appendicitis stories here. We would really love to hear from you!

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