Variations in the position of the appendix, age of the patient, and degree of inflammation make the clinical presentation of appendicitis notoriously inconsistent.
It is important to remember that the position of the appendix is variable. Of 100 patients undergoing 3-D multidetector CT, the base of the appendix was located at McBurney's point in only 4% of patients. In 36% of patients, the base was within 3 cm of McBurney's point; in 28%, it was 3-5 cm from McBurney's point; and, in 36% of patients, the base of the appendix was more than 5 cm from McBurney's point.
In addition, patients with many other disorders present with symptoms similar to those of appendicitis. Examples include the following:
Pelvic inflamatory disease(PID) or tubo-ovarian abscess
Endometriosis
Ovarian cyst or torsion
Ureterolithiasis and renal colic
Degenerating uterine leiomyomata
Diverculitis
Crohn disease
Colonic carcinoma
Rectus sheath hematoma
Cholecystitis
Bacterial enteritis
Mesenteric adenitis
Omental torsion
The classic history of anorexia and periumbilical pain followed by nausea, right lower quadrant (RLQ) pain, and vomiting occurs in only 50% of cases.
Migration of pain from the periumbilical area to the RLQ is the most discriminating feature of the patient's history. This finding has a sensitivity and specificity of approximately 80%. Positive likelihood ratio is 3.18 (2.41-4.21), and negative likelihood ratio is 0.5 (0.42-0.59).
When vomiting occurs, it nearly always follows the onset of pain. Vomiting that precedes pain is suggestive of intestinal obstruction, and the diagnosis of appendicitis should be reconsidered.
Nausea is present in 61-92% of patients; anorexia is present in 74-78% of patients. Neither finding is statistically different from findings in ED patients with other etiologies of abdominal pain.
Diarrhea or constipation is noted in as many as 18% of patients and should not be used to discard the possibility of appendicitis.
Duration of symptoms is less than 48 hours in approximately 80% of adults but tends to be longer in elderly persons and in those with perforation. Approximately 2% of patients report duration of pain in excess of 2 weeks.
A history of similar pain is reported in as many as 23% of cases. A history of similar pain, in and of itself, should not be used to rule out the possibility of appendicitis.
An inflamed appendix near the urinary bladder or ureter can cause irritative voiding symptoms and hematuria or pyuria. Cystitis in male patients is rare in the absence of instrumentation. Consider the possibility of an inflamed pelvic appendix in male patients with apparent cystitis.
Also consider the possibility of appendicitis in pediatric or adult patients who present with acute urinary retention.
Physical
RLQ tenderness is present in 96% of patients, but this is a nonspecific finding. Rarely, left lower quadrant (LLQ) tenderness has been the major manifestation in patients with situs inversus or in patients with a lengthy appendix that extends into the LLQ.
The most specific physical findings are rebound tenderness, pain on percussion, rigidity, and guarding.
The Rovsing sign (RLQ pain with palpation of the LLQ) suggests peritoneal irritation in the right lower quadrant precipitated by palpation at a remote location.
The obturator sign (RLQ pain with internal and external rotation of the flexed right hip) suggests that the inflamed appendix is located deep in the right hemipelvis.
The psoas sign (RLQ pain with extension of the right hip or with flexion of the right hip against resistance) suggests that an inflamed appendix is located along the course of the right psoas muscle.
These signs are present in a minority of patients with acute appendicitis. Their absence never should be used to rule out appendiceal inflammation.
Dunphy's sign (sharp pain in the RLQ elicited by a voluntary cough) may be helpful in making the clinical diagnosis of localized peritonitis. Similarly, RLQ pain in response to percussion of a remote quadrant of the abdomen, or to firm percussion of the patient's heel, suggests peritoneal inflammation.
The Markle sign, pain elicited in a certain area of the abdomen when the standing patient drops from standing on toes to the heels with a jarring landing, was studied in 190 patients undergoing appendectomy and found to have a sensitivity of 74%.
There is no evidence in the medical literature that the digital rectal examination (DRE) provides useful information in the evaluation of patients with suspected appendicitis; however, failure to perform a rectal examination is frequently cited in successful malpractice claims. In 2008, Sedlak et al studied 577 patients who underwent DRE as part of an evaluation for suspected appendicitis and found no value as a means of distinguishing patients with and without appendicitis.
Male infants and children occasionally present with an inflamed hemiscrotum due to migration of an inflamed appendix or pus through a patent processus vaginalis. This is often initially misdiagnosed as acute testicular torsion.
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