Ah, the appy. Every second-year med student can diagnose the acute onset of periumbilical pain that then localizes to the right lower quadrant. My first appy was a teenage girl who presented with pain, loss of appetite, fever, and dysuria for about twelve hours. Exam showed right lower quadrant tenderness. Labs were negative except for sterile pyuria. Even an obvious case like this one, where I walked out of the room and felt pretty sure, had a wrinkle, but sterile pyuria is a known associate, perhaps because the appendix can irritate either the ureter or the bladder.
But it's not until I read Cope that I look back on the appendicitis I missed in every single abdominal pain patient I've ever seen. Cope, incedentally, is the surgical bible of the acute abdomen. My surgery attending told us all to sit down and read it in a night, an 'easy read'. Perhaps, but to really absorb it...it's the book that keeps on giving. The following are some pearls to flesh out what we were taught in medical school.
History.
The 'march' of symptoms should be carefully sought, and is as follows: pain, followed by anorexia, nausea, or vomiting, followed by tenderness that is localizable but could be, according to Cope--and I love this--'somewhere in the abdomen or pelvis', followed by fever, followed by leukocytosis.
Put that in the context of what we think of as appendicitis. RLQ abdominal pain with a white count and fever. But a white count is the last finding. This march should be acute. Diagnosis of appendicitis should happen within 24 to 48 hours of onset, to avoid perforation. Fever first, nausea before pain, fifteen years of abdominal pain--these can make appendicitis less likely. Also, sudden onset of severe localizable pain, especially if it occurs in a 65-year old hypotensive veteran...perhaps not an appy.
Physical Exam.
This is the part of the reading that terrified me. The appendix can go anywhere in the abdominal cavity. Sweet. Frickin' awesome. I love that kind of a problem. If any localizable tenderness is found in the setting of a history that shows the above march, appendicitis should be on the list.
Of course McBurney's point must be palpated, and is perhaps the earliest localizable site of tenderness. Cope mentions light percussion as a very sensitive sign of parietal peritoneal irritation, which is what causes the tenderness--the switch from pain carried by the visceral peritoneal nerves to that carried by the parietal nerves. This can also cause hyperesthesia over the right lower quadrant to light touch. Test the psoas by rolling the patient to the left and extending the hip. Rovsing's sign is pain in the right with deep pressure on the left.
Perforation.
If the appendix does perforate, it can do so in a dizzying variety of ways. It can be localized or generalized, depending on whether it happens to be walled off or not. The most interesting difference, though, comes with rupture of an 'iliac' appendix versus the rupture of a 'pelvic' appendix.
The iliac appendix sits in the abdomen nestled against the pelvic girdle, while the pelvic appendix has dropped down behind the pelvic brim.
The iliac appendix should show a degree of guarding in the area we would expect, though, as in the case I started with, it can also produce urinary symptoms due to the proximity to the ureters. Overall, iliac appendiceal rupture should be found with a rudimentary exam of McBurney's point, which is reassuring since most people do that at least even when completing the intern's morning rounding exam (run in, stick stethoscope in the middle of the chest, push on tum, run out).
The pelvic appendix, though. Ah, the pelvic appendix. Much more terrifying. 'One of the most easily overlooked and therefore one of the most dangerous conditions that may occur in the abdomen'. Now that's saying a lot. A lot of badness can happen in one's abdomen. It's like a black box of poop-filled terror.
A perforated pelvic appendix may actually improve symptoms; the pain of distention is relieved (usually felt epigastrically) and the pus soup that was inside spills down deep in the pelvis, into the Pouch of Douglas.
So? SO, there will be little or no rigidity in the abdomen because the giant pus ball is in the pelvis. In fact, appendicitis can be misdiagnosed as PID, thereby lending insult--literally, if you're wrong and it's a young woman who is not sexually active--to injury. Things to watch for include pain with micturition, tenesmus, or diarrhea from inflammation. The cool maneuver here would be to rotate the hip internally to check for hypogastric pain, which would be wierd, right? Now, what if this is missed? It can go three or four days before the pus ball extends into the abdomen, and it tends to go to, wait for it, not the right, but the left side due to anatomy. Awesome.
See how I get paranoid? Now anyone who has abdominal pain in any location, with or without a fever, with our without nausea and vomiting, who may have diarrhea, pain with urination, pain with defacation, that has or has not been constant, probably has either early, late, missed, or atypical appendicitis and a giant collection of bacteria waiting to make them toxic and die.
This is how I think.