Zinc and acute tropical ulcers in Gambian children and adolescents.

28 Gambian children and adolescents with acute tropical leg ulcers entered a double blind trial of oral zinc supplements as an adjunct to standard treatment. Analysis of the area healing of the ulcers resulted in a mathematical expression which showed that for each subject re-epithelialization reduced the ulcer radius at a constant healing rate (k). k was derived from the equation At = pi X (r - k X t)2, where At = residual ulcer area at time "t", r = initial ulcer radius and t = time from start of treatment. In the zinc treated group k was 0.55 +/- 0.39 mm/day, and 0.51 +/- 0.25 mm/day in the placebo group. The initial low plasma zinc of 6.5 +/- 1.9 mumol/L in the ulcerated subjects was not significantly lower than that of 7.5 +/- 3.6 mumol/L in the nonulcerated controls. Oral zinc supplements significantly elevated plasma zinc concentrations by 5.8 +/- 4.8 mumol/L compared to the placebo group's change of 0.4 +/- 2.0 mumol/L (p less than 0.001). Plasma alkaline phosphatase activities and fatty acid profiles did not change with zinc supplementation. Thus unequivocal clinical and biochemical evidence of zinc deficiency in these ulcerated subjects was not established, despite changes in plasma zinc. This study does not indicate any role for zinc supplementation in the management of acute tropical ulcers.