This is one of the hoary chestnuts of clinical surgery, and the usual academic list for students can still be a problem after some years of practice. Obstructive appendicitis can give the same episodic pain and make the patient roll around and vomit frequ ently as ureteric colic, and occasionally I get an IVP done.
About 3 years ago a very very fat teenage girl got sicker and sicker for a couple of days after I removed her appendix laparoscopically for Right abdominal pain. Only some “fishing for a diagnosis” with a CT scan clarified her right renal pyonephrosis wit h an obstructing calculus mid-ureter. This was drained by the radiologists and later managed by the (helpful) urologists.
A more common problem is the patient with RIF pain from some other cause. I recognise the following conditions:
1. School phobia or manipulation of parents
2. Irritable bowel in children who rush to school and whose parents don’t make time for bran or other fibre cereal, and for an unhurried bowel action. I mostly ask for details of breakfast.
3. Abdominal migraine – episodic RIF pain with fever, preceded by typical hemicrania and visual fortification spectra, which aren’t mentioned unless you specifically ask. For reasons I don’t understand, this responds to cycloheptidine for two or three wee ks, and doesn’t recur. It may also increase appetite and unwanted weight gain.
4. Neuropathy: The cutaneous nerve which emerges through a neurovascular hilum at the lateral edge of the right lower rectus abdominis can be damaged or irritated by scarring from an unco-ordinated muscle contraction during some awkward movement.
The RIF pain comes in spontaneous bouts lasting hours or days, sometimes with vomiting, which puzzles me. There is localised tenderness which persists when the abdominal muscles are tensed, and a milder pain is reproduced consistently by some trunk movements.
These signs are abolished by accurate infiltration with local anaesthetic with the muscles tensed to help define the layers. Longer relief occurs (sometimes needing a second injection), perhaps because the scar is disrupted by the distension so that a neurom a is no longer squeezed.
Once every few years I do an open neurolysis at the point of emergence of the nerve, which is easy to sever. On one such occasion the pathologist reported traumatic neuroma.
One female of 18 from some distance away had these features, but in the left iliac fossa and not the RIF. To her amazement I asked if she was left-handed. To my surprise and satisfaction she said yes. I think this condition is due to an awkward heavy move ment with the dominant arm.
5. Others – threadworms, foreign bodies in appendix, foreign body perforation of nearby ileum, torsion of small tongue of omentum etc etc.
There’s more to say, but I’m more interested in the differential diagnoses of others.