acute appendicitis: how good are your diagnostic skills?

AAFP REVIEW ARTICLE KEY POINTS:

COMMON SYMPTOMS (frequency in %):

• abdominal pain ~100%
• anorexia ~100%
• nausea 90%
• vomiting 75%
• pain migration 50%
• Classic symptom sequence (vague periumbilical pain to anorexia/nausea/unsustained vomiting to migration of pain to right lower quadrant to low-grade fever) 50%

SYMPTOM/SIGN (positive likelihood ratio--increased likelihood you have an appy if you have this):

• RLQ pain (8.0)
• pain migration (3.2)
• pain before vomiting (2.8)
• anorexia, nausea & vomiting (<2.8)
• psoas sign (2.38)
• rebound tenderness (variable, 1.1 to 6.3)
• fever (1.9)

IMAGING:

• ultrasound: sensitivity 85%, specificity 92%
• CT: sensitivity 90-100%, specificity 95-97%

BOTTOM LINE:
--most common: abd pain, anorexia, nausea/vomiting, migratory pain
--most useful: RLQ pain, migratory pain, pain before vomiting
--ultrasound is pretty accurate, CT is really accurate, but neither are perfect
--none are truly absolute, think of appy, but also think past appy

Reference(s): AAFP review on appendicitis, tangential craziness