Other problems in tropical surgery

There are many of these. Here are some of the various conditions you may meet, and which are not discussed elsewhere.

MORE TROPICAL PROBLEMS ONCHOCERCAL NODULES If a patient from an endemic area has firm, 2 or 3 cm, NODULES especially over his iliac crests, trochanters, sacrum, knees, shoulders, or head, they are probably onchocercal nodules. These are well-encapsulated, and easy to remove under local anaesthesia.

ENCYSTED GUINEA WORMS See also Fig. 7-1 (the differential diagnosis from pyomyositis).

If a guinea worm PRESENTS ON THE SKIN, don't try to dissect it out, because severe sepsis usually follows. Instead, carefully wind it round a match-stick, and be prepared to take 3 weeks in doing so, leaving the stick with its coil of worm under a dressing, and pulling out a little more each day.

If a large rubbery CYSTIC MASS develops, usually on his trunk, and typically on his back near the angle of his scapula, distinguish a guinea worm cyst (a low-grade encapsulated abscess) from a lipoma. (1) A guinea worm cyst often has a small scar on its surface. (2) Ask him to contract his muscles: a lipoma is usually superficial, and a guinea worm deep to them. (3) Aspirate the mass with a wide needle. A guinea worm cyst usually contains sterile pus. If necessary dissect out the mass, taking care not to injure surrounding structures. There is no easy plane of cleavage.

CURIOUS FORMS OF GANGRENE If the TIPS OF HIS FINGERS AND TOES BECOME GANGRENOUS without any obvious cause, one of the possibilities is ''tropical coagulopathic ischaemia', also known as ''idiopathic gangrene', which is not uncommon in sub-Saharan Africa. You will see it at any age, but particularly in malnourished children with severe infections. The arteries and veins of all four limbs may be filled with clot, so that a whole limb or a large part of a limb is lost.

The disease starts with swelling, which soon becomes severely painful. The peripheral pulses disappear, after which gangrene may be rapid or slow, new areas of gangrene appearing over several months. The process eventually stops spontaneously. If gangrene is extensive the mortality rate is high. It may be a manifestation of the same process that causes cancrum oris (26.6).

AINHUM If a CONSTRICTING GROOVE FORMS ROUND THE BASE OF A PATIENT'S TOE, usually the 5th, he has that mysterious disease called AINHUM. This occurs in otherwise healthy barefooted people, is painful because of the ischaemia it causes, and can be a severe disability. It may last several years, before the end of the toe finally falls off.

Tetanus is a possible complication, so give him two doses of tetanus toxoid a month apart. Clean his toes thoroughly. Then, under local anaesthesia, amputate his toe using a dorsal racquet incision (shown as H, Fig 75-30 for a little finger) encircling the base of his toe, just proximal to the constricting groove, and exposing its MP joint. Dislocate this with the rest of the stump of his proximal phalanx. Results are good; after perhaps years of pain he will now have a stable painless foot, but without his little toe.

Miller JRM. ''Tropical coagulopathic ischaemia' Proceedings of the Association of Surgeons of East Africa 1980;3:84[nd]88.[-3] Bhana D and Baddeley H ''Idiopathic gangrene''. East African Medical Journal 1970;47:506[nd]14