1. A diagrammatic representation was included in the original article. Since the article was published as a brief report, we deleted it. We used 6 batteries of 1.5 volts each. A single battery of 9 volts should serve the same purpose.

We did not use any device to increase or decrease the current value, but we monitored the current. The average current achieved with our method was 2 mA with a maximum of 3 mA. Without any device to control the current, the success rate was 80% in first attempt. Complication in form of minor burns occurred in 10 out of 757 patients. If the observed current value was less than 1.5 mA, iontophoresis was repeated.

The results are reasonable in resource poor setting. The aim of presenting our experience is not to replace the sophisticated equipments but to show that acceptable results can be achieved with low cost equipment. If we use devices to control the current it will increase the cost.

2. We collected sweat on a filter paper. The filter paper was placed on the skin and then a strip of cling film was wrapped around the forearm covering the filter paper, making the system air-tight. There was hardly any potential space between skin and cling film. However, if a thicker, less pliable, transparent plastic film is used in place of cling film, there is a possibility of condensation below plastic film. We did not encounter this problem with cling film.

3. The average sweat weight was between 200-300 mg. Since sweat is aqueous and we provided an elution time of at least 12 hours, there should not be any problem to elute different amounts of sweat in this fixed volume of 8 mL. A variable amount of distilled water could be used to elute different sweat weights, however, this will make calculations more cumbersome.

4. Two of these four patients were finally categorized as cystic fibrosis.

5. We regret the error in the text. In twenty-nine patients, adequate sweat could not be collected in the second attempt.