Clinical aspects of Tropical Sprue

Tropical sprue can have an insidious onset or can start acutely. The symptoms are those of chronic malabsorption. Generally it presents as a clinical triad of painful tongue, loss of weight and persistent abdominal discomfort with diarrhoea. Patients are noticeably tired, both physically and mentally. Amenorrhoea is very common. There is loss of weight with muscle atrophy. Hypoalbuminaemia leads to oedema.

Due to malabsorption of carbohydrates there is increased gas production in the intestines, with borborygma, a bloated feeling in the abdomen and intestinal cramps. The D-xylose absorption test is abnormal in more than 90% of cases. Fat malabsorption leads to steatorrhoea with more than 10 g of fat in the faeces. This occurs in 95% of patients. The stools are pale, very odorous and quite voluminous, up to 5 times the normal amount. Dehydration, hyponatraemia and hypokalaemia are very common.

Calcium deficiency may lead to tetany with positive Trousseau’s sign [in latent tetany, the occurrence of carpopedal spasms accompanied by paresthesia elicided when the upper arm is compressed (diminished blood supply), such as by a tourniquet or a blood pressure cuff. It occurs when the concentration of ionised free calcium is below a certain treshold; this concentration is pH-dependent].

Hypokalaemia leads to reduced tendon reflexes and abnormalities on the electrocardiogram. There is usually a deficiency of vitamin B12, folic acid and sometimes also iron. Anaemia occurs and is typically macrocytic with megaloblastic bone marrow.

In long-term cobalamine deficiency there may be peripheral neuritis and involvement of the spinal cord, chiefly of the dorsal columns (proprioception). The tongue is red and painful. As well as glossitis there may be stomatitis with superficial erosions.

Deficiencies in fat-soluble vitamins (A, D, E, K) lead to prolongation of the coagulation time and osteomalacia.

Vitamin A deficiency is characterised by a dry, rough skin with follicular hyperplasia and Bitot’s spots on the conjunctivae. In severe deficiency night-blindness and xerophthalmia may occur.

Category: Medical Subject Notes , Medicine Notes