Sweat Stimulation Research Articles

Sweat testing for cystic fibrosis: How good is your laboratory?

Sweat testing for cystic fibrosis: How good is your laboratory?

Reliability of sweat‐testing by the Macroduct® collection method combined with conductivity analysis in comparison with the classic Gibson and Cooke technique

This study was to ascertain the reliability of sweat‐testing by the Macroduct collection method combined with conductivity analysis (MCS) compared with the Gibson and Cooke technique (GCT). Sweat stimulation by pilocarpine iontophoresis was identical for both procedures, sweat being collected for 30 min on a filter paper on one forearm and in the coil of the Macroduct® collector on the other. Chloride, sodium and potassium concentrations were chemically analysed both on paper‐eluted and tube‐collected sweat; the latter was also analysed using a conductivity analyser. Chemical analyses were compared with conductivity analyses. This prospective study was carried out on 318 subjects with MCS (118 CFs, 200 controls) and on 305 of them with the GCT (113 CFs, 192 controls). The pilocarpine iontophoresis produced adequate sweat in 96.4% of collections with GCT and in 90.9% with the MCS. Sensitivity and specificity of the Macroduct®/ conductivity system were comparable to the GCT. No patient detected by the GCT technique was considered negative by conductivity, but one GCT positive was “borderline” with the MCS. Six non‐CF subjects identified as negative by the GCT (3.3%) were in the borderline range with the MCS. Conclusion: Sweat‐testing by the MCS has acceptable sensitivity and specificity when performed by trained CF sweat‐testing technicians. Additional studies will be required to find out if these results can be confirmed in small clinics and hospitals where testing is done infrequently. Wherever the MCS is used all positive or borderline results should be confirmed by the GCT at a reference Cystic Fibrosis Center.

Baseline water loss and cholinergic sweat stimulation in atopic dermatitis: a gravimetric measurement of local skin water loss

The sweat gland function in atopic dermatitis (AD) and in respiratory atopy is a matter of controversy. We examined the baseline water loss and local sweating response in non-eczematous back skin of 146 young men: pure AD, AD with rhinitis/asthma, rhinitis/asthma alone, non-atopic dermatosis and non-atopic healthy. All AD subjects were further divided into the subgroups AD dry and AD normal skin. Following injections of saline and a high concentration of methacholine (5 x 10(4) mol/l) into separate sites the moisture losses were collected into closed pads over a period of 40 min. The baseline water loss was significantly increased (P less than 0.001) and median pure sweat loss was significantly decreased (P less than 0.01) in AD compared with nonatopic healthy individuals. These trends were accentuated in AD dry skin. Respiratory symptoms had no appreciable influence on results. A depressed sweating response occurred in 30% of AD subjects and 9% of non-AD subjects. An elevated baseline water loss value and a depressed sweat loss value coexisted in 22% of subjects with AD dry skin compared with 3% of the non-atopics.

Local sweat stimulation with the skin prick technique

Intracutaneous injections of cholinergic agonists are usually employed for induction of local sweating. The possibility to apply a less painful skin prick technique as a sweat test was examined. Pricks were made on the forearm skin of 25 young men by puncturing the skin through drops of methacholine (MCH) and control saline solutions with lancets having a point length of 1 mm. The drops were kept on skin for 10 min and were then wiped off. Using an evaporimeter the measurements of water loss (WL) were started 5 min later and continued at 5 min intervals. Sweat loss (SL) was calculated from the difference of rates of evaporative WL recorded at the MCH and saline pricks. Ten, 1, 0.1, and 0.01% solutions of MCH elicited the following average peak evaporative sweat losses: 107.1, 77.5, 32.4 and 5.4 g m-2h-1. Both the degree and duration of the sweat responses were dependent on concentration. The prick technique is well tolerated and may serve for comparative studies of local sweating.

Equine anhidrosis: a review of pathophysiologic mechanisms.

Anhidrosis is loss of the ability to sweat. The problem is seen in horses kept in a hot humid climate, and it may cause severe impairment of thermoregulation in the equine athlete. British Thoroughbreds imported to her tropical colonies are the earliest recorded cases, and since then the syndrome has come to be described as one of Thoroughbreds, usually performance athletes, undergoing acclimatization to heat and humidity. A recent epidemiologic study of cases in Florida has shown, however, that many different breeds, and long time inhabitants of a hot climate, may be affected. Equine sweat glands are of the apocrine type, and sweating is stimulated by direct local release of epinephrine from adrenergic nerve endings and by circulating epinephrine. Lack of sweating could be due to a number of possible flaws in a sequence from central nervous stimulation through sweat stimulation and secretion to delivery of sweat to the skin surface. The most likely possibilities are inadequate sweat gland response due to habituation of receptors to a high circulating level of epinephrine and occlusion of the sweat ducts by keratin plugs. Hormonal or metabolic imbalance may play a role both in the onset and secondary signs associated with anhidrosis.

The significance of the local sweat response in assessing the progress of leprosy.

Serial observations on cutaneous sensation and on sweat response in hypopigmented flat patches of twenty-nine patients with tuberculoid and five with dimorphous leprosy on dapsone therapy were studied over 2 years. Sensation was determined by routine methods, while sweat stimulation was done by intradermal injection of 0-1 ml (0.025 mg) of carbachol (carbaminoylcholine). There was significant improvement in sensation and considerable augmentation of sweat response in the final as compared to the initial tests. The difference in sweat response was statistically significant, suggesting the value of this simple procedure in assessing the progress of leprosy.

A METHOD FOR SWEAT STIMULATION AND COLLECTION.

SPECIAL COMMUNICATIONSA method for sweat stimulation and collectionRichard L. Dobson, and Arnold C. RatnerRichard L. Dobson, and Arnold C. RatnerPublished Online:01 Sep 1963https://doi.org/10.1152/jappl.1963.18.5.1038MoreSectionsPDF (389 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat "A method for sweat stimulation and collection." Journal of Applied Physiology, 18(5), p. 1038 Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByThe evolution of eccrine sweat gland research towards developing a model for human sweat gland function6 June 2018 | Experimental Dermatology, Vol. 27, No. 5 More from this issue > Volume 18Issue 5September 1963Pages 1038-1038 Copyright & PermissionsCopyright © 1963 the American Physiological Societyhttps://doi.org/10.1152/jappl.1963.18.5.1038PubMed14063247History Published online 1 September 1963 Published in print 1 September 1963 Metrics