Premium
Dose thresholds and duration of the local anhidrotic effect of botulinum toxin injections: measured by sudometry
Author(s) -
Braune C.,
Erbguth F.,
Birklein F.
Publication year - 2001
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1046/j.1365-2133.2001.03961.x
Subject(s) - botulinum toxin , duration (music) , medicine , pharmacology , anesthesia , physics , acoustics
Background Local injections of botulinum toxin type A (BTX‐A) have been used successfully to treat focal hyperhidrosis, but because experimental data were lacking, doses have been chosen arbitrarily or empirically. Objectives To analyse dose dependency and duration of BTX‐A‐derived suppression of sweat gland activity. Methods Employing a standardized scheme (four injections, square 2 × 2 cm), different doses of BTX‐A [Dysport ® ; 2·5–120 mouse units (MU)] were injected subcutaneously at the lateral aspects of both of the lower legs in 15 healthy volunteers. Sweat tests were performed before, and 3 weeks and 6 months after, BTX‐A injections. Sweating was visualized by staining with iodine starch, and quantified by capacitance hygrometry after carbachol iontophoresis, the quantitative sudomotor axon reflex test (QSART). Results Iodine starch staining indicated a threshold dose of 10 MU (2·5 MU cm −2 ) leading to visible anhidrotic skin spots after 3 weeks in all subjects. This was maintained for 6 months with doses of 50 MU (12·5 MU cm −2 ) or higher, but the size of the anhidrotic skin area decreased over time ( P < 0·001) indicating partial recovery at the edges. After 3 weeks QSART was significantly reduced ( P < 0·02) and completely suppressed by doses of 80 MU (20 MU cm −2 ) or more, although after 6 months QSART increased again to pre‐BTX‐A levels ( P < 0·001). Both methods indicated that the suppression of sweating is dose dependent (QSART: r = −0·70, P < 0·001; iodine starch staining: r = 0·74, P < 0·001). Conclusions Our findings suggest that BTX‐A effectiveness can be quantified by testing sudomotor function. For the first time threshold doses for the suppression of sweating have been defined.