Gangrenous lesions may occur in amoebic dysentery although more common in bacillary infections. Such cases will show extreme prostration and even give the clinical picture of cholera.
Complications.—By far the most important and serious complication of amoebic dysentery is liver abscess, which occurs in about 20% of cases. This condition is treated of separately. Besides liver abscess quite a number of cases of amoebic abscess of the brain have been reported, 26 such cases occurring in Egypt alone. These abscesses almost always occur in those cases which have developed liver abscess and may appear after the liver abscess has healed.
The pus of such abscesses is viscid and blood-tinged, resembling liver abscess pus. The amoebae are found in the abscess wall. The symptoms are those of brain tumor, meningitis not occurring. Necrotic processes of skin and muscles have also been reported in which amoebae have been found.
Perforation of the large intestine is not rare, Strong having noted 12 perforations in 77 autopsies. These usually occur in the region of the sigmoid flexure.
Adhesions are common complications of amoebic dysentery.
Diagnosis
Clinical Diagnosis.—In the clinical diagnosis it is well to remember that many cases of chronic tropical diarrhoeas are really due to amoebic ulcerations of the intestines.
We can as a rule differentiate bacillary from amoebic dysentery by the more sudden and acute onset of the former together with fever and other evidences of toxaemia. The pulse rate is more rapid in bacillary than amoebic dysentery. Again the number of stools in bacillary dysentery is usually greater and the amount of each stool less in quantity. The stool of bacillary dysentery is of a milky whiteness from the large number of pus cells or composed of gelatinous, reddish mucus, while that of amoebic dysentery is tinged with disintegrated blood giving it a grayish-green or brown color. The mucopurulent mass in bacillary dysentery may be flecked or streaked with blood. The therapeutic results following emetine injections are of value in diagnosis.
Gangrenous types of dysentery are similar whether due to bacillary or amoebic infection. Chronic dysentery of bacillary origin is much like amoebic dysentery clinically.
Manson-Bahr and Gregg recommend the use of the sigmoidoscope in the diagnosis of chronic amoebic ulcerations. In the evening the patient takes ½ ounce of castor oil and the next morning a soap and water enema is given followed by 15 minims of laudanum. The patient is put in the lithotomy position. No anaesthetic is used. The pain in introducing the instrument is greater in chronic bacillary ulceration cases than in amoebic ones. Scrapings can be made for microscopic examinations. Nisbet has reported the diagnosis of a case of balantidial ulceration by use of the sigmoidoscope.