Interesting Appendix!

One of the most common causes of severe acute abdominal pain worldwide.
A correctly diagnosed non-acute form of appendicitis is known as "rumbling appendicitis".
The term "pseudoappendicitis" is used to describe a condition mimicking appendicitis. It can be associated with Yersinia enterocolitica.

Picture shows an acutely inflamed and enlarged appendix, sliced lengthwise.

Rovsing's sign
Continuous deep palpation starting from the left iliac fossa upwards (counterclockwise along the colon) may cause pain in the right iliac fossa, by pushing bowel contents towards the ileocaecal valve and thus increasing pressure around the appendix.

Psoas sign or "Obraztsova's sign"
is right lower-quadrant pain that is produced with either the passive extension of the patient's right hip (patient lying on left side, with knee in flexion) or by the patient's active flexion of the right hip while supine. The pain elicited is due to inflammation of the peritoneum overlying the iliopsoas muscles and inflammation of the psoas muscles themselves. Straightening out the leg causes pain because it stretches these muscles, while flexing the hip activates the iliopsoas and therefore also causes pain.

Obturator sign
If an inflamed appendix is in contact with the obturator internus, spasm of the muscle can be demonstrated by flexing and internal rotation of the hip. This maneuver will cause pain in the hypogastrium.

Dunphy's sign
Increased pain in the right lower quadrant with coughing

Kocher's (Kosher's) sign
From the history given, the appearance of pain in the epigastric region or around the stomach at the beginning of disease with a subsequent shift to the right iliac region.

Differential diagnosis
In children
Gastroenteritis, mesenteric adenitis, Meckel's diverticulitis, intussusception, Henoch-Schönlein purpura, lobar pneumonia, urinary tract infection, new-onset Crohn's disease or ulcerative colitis, pancreatitis, abdominal trauma from child abuse, distal intestinal obstruction syndrome in children with cystic fibrosis, typhlitis in children with leukemia;

Courtesy: Wikipedia: http://en.wikipedia.org/wiki/Appendicitis