Diagnostic Considerations
The signs and symptoms of appendicitis are nonspecific and are common with other diagnoses. Do not diagnose gastroenteritis rather than appendicitis unless the patient has nausea, vomiting, and diarrhea. Even with the presence of vomiting and diarrhea, consider the unusual presentations of retrocecal or pelvic appendicitis. Additionally, appendicitis can develop as a sequela of gastroenteritis associated with lymphoid hyperplasia.
Diagnose abdominal pain of unknown etiology in patients with nonspecific abdominal symptoms if a diagnosis cannot be established. These patients may be discharged with close follow up. Instruct patients to be reevaluated in 8-12 hours by their primary care physician or to return to the emergency department. Patients with equivocal examination findings but suspected to have early appendicitis should be admitted for observation for serial abdominal examinations or to undergo imaging with ultrasonography or abdominal CT scanning.
If constipation is diagnosed and treated with enemas and/or stool softeners with resolution of the signs and symptoms, inform the patient and family that recurrence of the abdominal pain in the future could be recurrent constipation or acute appendicitis and to seek medical advice.
Appendicitis should be considered in special patient populations, such as the immunocompromised and developmentally delayed. Appendicitis is rare in infants. If an infant has appendicitis, the diagnosis of Hirschsprung disease should also be considered.
Other problems to consider include the following:
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Ovarian cyst
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Ovarian torsion
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Pelvic inflammatory disease (PID)
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Pregnancy
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Ectopic pregnancy
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Renal calculi
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Mesenteric lymphadenitis
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Mittelschmerz
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Pneumonia (right lower lobe)
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Neutropenic typhilitis
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Lymphoma
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Epiploic appendagitis
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Paratubal cysts
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Volvulus
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Typhlitis
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Omental torsion
The major differential diagnoses for acute appendiceal abscess or mass include Crohn disease and malignancy.
Differential Diagnoses
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Ectopic Pregnancy
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Ovarian Torsion
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Ultrasonographic examination of the right lower quadrant reveals a greater than 6-mm noncompressible tubular structure shown in cross section. Discomfort was noted as the probe was depressed over this structure. A small amount of free fluid is also noted surrounding the appendix.
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Ultrasonographic examination of the right lower quadrant reveals a greater than 6-mm noncompressible tubular structure shown in cross section. Discomfort was noted as the probe was depressed over this structure. A small amount of free fluid is also noted surrounding the appendix.
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CT scan depicting a distended tubular structure descending into the pelvis and containing a round calcification (ie, an appendicolith).
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CT scan revealing an enhancing tubular structure descending into the pelvis. Periappendiceal inflammation and streaking, so-called dirty fat, is noted surrounding the appendix.
