Acute and chronic appendicitis: causes, symptoms, diagnosis and treatment

By Cristiano Antonino Last updated Jun 8, 2023

The term ‘appendicitis’ refers in the medical field to the inflammation – acute or chronic – of the vermiform appendix (also called the caecal appendix or just the ‘appendix’), i.e. the tubular formation forming part of the large intestine (more precisely its proximal segment, called the ‘cecum’)

Diffusion of appendicitis

Appendicitis is one of the most common and significant causes of severe and sudden abdominal pain worldwide.

There are currently around 16 million cases per year worldwide, resulting in approximately 70,000 deaths.

Causes and risk factors of appendicitis

Appendicitis is caused by an obstruction of the appendix cavity, which may be due to coprolites, inflammation of viral origin in the lymphoid tissue, parasites, gallstones, neoplasms or other causes.

Appendicitis is most frequently caused by calcification of the faeces.

Inflamed lymphoid tissue from a viral infection, parasites, gallstones or neoplasms can also cause obstruction in a large number of cases.

The obstruction leads to increased pressure in the appendix, decreased blood flow to the appendix tissues and bacterial overgrowth within, which is the direct cause of the inflammation.

The combination of inflammation, reduced blood flow to the appendix and its distension causes tissue injury and necrosis (death).

If this process is not treated, the appendix can burst releasing bacteria into the abdominal cavity, resulting in severe abdominal pain and the occurrence of complications.

Symptoms and signs of appendicitis

The most common symptoms include:

right lower quadrant abdominal pain,
nausea,
vomiting,
anorexia (decreased appetite).

The fever is usually not very high with values around 38 °C.

Both diarrhoea and constipation may be present.

However, about 40% of cases do not present these typical symptoms.

The pain is usually localised to the epigastric or mesogastric site, which then localises to the right iliac fossa, but sometimes the pain is localised to sites even farther apart and may mimic a right biliary or renal colic (ascending retrocecal appendix) or a bladder or gynaecological pathology (pelvic appendix).

Serious complications that can occur if the appendix ruptures are peritonitis and sepsis.

The diagnosis of appendicitis is largely based on the patient’s signs and symptoms

In many cases, an accurate anamnesis and a precise objective test are enough for the doctor to point towards the diagnosis of inflammation of the appendix.

Typically found in the patient is a vague pain in the epigastric location later localised to the ileo-cecal location and accompanied by anorexia, nausea and vomiting depicting an acute attack.

Laboratory tests and imaging techniques may be useful in confirming the diagnosis, but here I would like to emphasise how important semeiotics is in the rapid diagnosis of appendicitis.

Finding pain at specific points or the positivity of certain manoeuvres can provide important indications.

In this regard, let us recall some manoeuvres that are useful in diagnosis:

Blumberg manoeuvre. This manoeuvre consists of gently resting the fingers of the hand on the patient’s abdominal wall, sinking it gradually (first phase) and then lifting it suddenly (second phase). It is called positive if the pain the patient feels during the first phase of the manoeuvre is modest, in the second phase it increases in intensity becoming violent.
Rovsing manoeuvre. Using the fingers and palm of the hand, pressure is applied to the abdomen at the level of the left iliac fossa. Then the hand is moved progressively upwards to compress the descending colon. If the manoeuvre evokes pain in the right iliac fossa, it is said to be positive and is an inconstant sign of acute appendicitis.
Psoas manoeuvre. The patient lies in left decubitus (or, alternatively, prone), and one goes to hyperextend the thigh on the hip, with a stiff knee, putting the psoas (whose normal function is to flex the thigh) under tension. This manoeuvre causes pain if there is appendicitis, and in particular is an indication of retrocecal localisation of the appendix.
McBurney’s point. Pressure at McBurney’s point is painful in cases of acute appendicitis.

Laboratory tests

In appendicitis there is a simultaneous alteration of several laboratory parameters.

In particular, significant neutrophilic leucocytosis must be present.

The magnitude of the values, which may range from 10-19,000, however, does not always reflect the severity of the clinical picture, while values > 20,000 may be indicative of peritonitis as a consequence of organ perforation.

Diagnostic imaging

The two most common imaging tests to confirm appendicitis are abdominal ultrasound and computed tomography (CT).

Direct X-ray of the abdomen or MRI is also useful.

CT has been shown to be more accurate than ultrasound in detecting acute appendicitis, however, it may be preferred as the first imaging test in children and pregnant women as it does not carry the risks associated with exposure to ionising radiation as with CT.

Endoscopic and radiographic techniques with contrast medium are generally excluded due to the risk of perforation of the inflamed appendix (but also of the cecum).

Differential diagnosis plays a key role in suspected cases of appendicitis

Of acute appendicitis that goes to surgery, only in about 50% of cases is there an objective intra-operative finding and histological confirmation.

In the other cases, the surgeon finds a white appendix (i.e. with no signs of inflammation) and only in a very small part, calculated at around 10-20%, can he trace the pathology that triggered the appendicular-type picture.

Risks

Serious complications that can occur if the appendix ruptures and bacteria leak into the abdomen are peritonitis and sepsis.

Treatment

The typical treatment for acute appendicitis is surgical removal of the appendix, which can be performed through an open incision in the abdomen (laparotomy) or laparoscopically (less invasive, with longer surgical time but shorter postoperative recovery time).

Surgery reduces the risk of side effects related to ruptured appendix.

Antibiotics can be equally effective in some cases of unruptured appendicitis.

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