The liver cells in the area of the central veins show the most marked destruction. The myocardium shows fatty change and the fat lipoid content of the adrenal is reduced.
The anuria is thought to be mechanical and due to the plugging up of the tubules by haemoglobin casts.
The urine shows a reddish to black color and has a sediment made up of granular débris with haematoidin crystals and only rarely a red cell. It is not a haematuria.
The absorption bands of methaemoglobin are usually noted spectroscopically.
Urobilin and albumin are present in large quantities.
Symptomatology
A Typical Case.—In a person who has lived in an intensely malarious region for one or two years or even long after he has left such districts and who has had several malarial attacks, there comes on what is considered as another malarial chill, which may or may not definitely be connected with some resistance-lowering influence, as exposure to tropical sun or rain, or indulgence in dietary or other excesses, or following in one to six hours the accustomed dose of quinine. This chill, however, is more prostrating than those formerly experienced and upon passing his urine the patient notes its reddish to black coffee color and himself makes the diagnosis of blackwater fever. The attack comes on suddenly with a very severe chill, marked prostration and pain over the region of the kidneys. The temperature in a typical case rapidly goes up to 104° to 105°F.
Rather profuse sweating accompanies the fall of the fever and the patient is markedly debilitated after the subsidence of the fever. There may be a recurrence of the paroxysm the following day. The fever course, however, may be more or less continuous or remittent. In other words it tends to be irregular and atypical.
Nausea and bilious vomiting come on early with epigastric distress. Almost as pathognomonic as the haemoglobinuria is the early and intense jaundice. This comes on within a few hours or almost simultaneously with the haemoglobinuria and usually lasts for two or three days after the haemoglobinuria and fever have ceased. Itching of the skin of this jaundice is not noticeable.
The spleen and liver are enlarged and tender. Albuminuria comes on with the haemoglobinuria and shows from 1/10 to 4/10 of 1% of albumen by weight.