Appendicitis is one of the most common surgical emergencies. Despite advances in laboratory testing and imaging, accurate diagnosis of appendicitis remains a challenge. Complications from misdiagnosis of appendicitis include intraabdominal abscess, wound infection, adhesion formation, bowel obstruction, and infertility.
The most reliable symptom in appendicitis is abdominal pain. The early signs of appendicitis are quite nonspecific and progress with time. The location of the pain depends on the location of the appendix. Pain commonly begins in the periumbilical or epigastric region. As peritoneal irritation occurs, the pain will often localize to the right lower quadrant. Other symptoms associated with appendicitis include anorexia, nausea, and vomiting but these symptoms are neither sensitive nor specific. As the pain increases, irritation of the bladder and/or colon may cause dysuria, tenesmus, or other symptoms. Many patients have the “bump” sign, where the patient notes an increase in the abdominal pain associated with bumps in the ride to the hospital. If the pain suddenly decreases the examiner should consider appendiceal perforation.
The classic point of maximal tenderness is in the right lower quadrant just below the middle of a line connecting the umbilicus and the right anterior superior iliac spine. (McBurney's point). Patients may also have pain referred to the right lower quadrant when palpating the left lower quadrant (Rovsing sign), pain elicited by extending the right leg to the hip while lying in the left lateral decubitus position (psoas sign), or pain elicited by passively flexing the right hip and knee and internally rotating the hip (obturator sign). Patients with a pelvic appendix may be quite tender on rectal examination, and patients with a retrocecal appendix may have more prominent flank pain than abdominal pain. No individual physical finding is sensitive or specific enough to rule in or rule out the diagnosis.
Fever is a relatively late finding in appendicitis and rarely exceeds 39°C (102.2°F), unless rupture or other complications occur.
The diagnosis of acute appendicitis is primarily clinical. Symptoms with high sensitivity for appendicitis include right lower quadrant pain, pain that occurs before vomiting, and absence of prior similar pain. Migration of the pain is thought to be highly specific for appendicitis. Physical signs with high specificity include right lower abdominal rigidity and positive psoas sign. Additional studies, such as complete blood count, C-reactive protein, urinalysis, and imaging studies, may be performed if the diagnosis is unclear. A pregnancy test must be performed in all females of reproductive age. A normal WBC does not rule out appendicitis. Urinalysis is useful to help rule out other diagnoses but pyuria and hematuria can occur when an inflamed appendix irritates the ureter.
The differential diagnosis of right lower quadrant pain is wide and includes other gastrointestinal processes (eg, inflammatory bowel disease, hernia, abscess, volvulus, diverticulitis), gynecologic or urological processes (eg, ectopic pregnancy, ovarian torsion, renal colic, genitourinary (GU) infection or abscess), or musculoskeletal processes (eg, muscular hematoma or ...