Dysport dosing for primary axillary hyperhidrosis
Use 100–150 Units of abobotulinumtoxinA (Dysport) per axilla, delivered intradermally in a multi-point grid over the starch-iodine–mapped area; start at 100 U/axilla and escalate to 150 U/axilla if prior cycle duration is <6 months. 1, 2
- Rationale (mortality, morbidity, QOL):
- Botulinum toxin A markedly reduces sweating and improves quality of life with low morbidity; doses of 100 vs 200 U/axilla showed equivalent efficacy and durability, favoring the lower dose to minimize exposure and cost without sacrificing benefit 1. Longer first-cycle response (≥6 months) predicts fewer treatments over time, supporting dose titration based on prior durability (QOL optimization) 2.
- No high-quality guideline or FDA Dysport label addresses hyperhidrosis dosing; therefore, the most recent/highest-quality directly applicable studies are prioritized.
How to dose and inject
- Dose per axilla:
- First treatment: 100 U.
- If prior duration <6 months, use 150 U at next session.
- Dilution and delivery:
- Reconstitute to allow small intradermal blebs (e.g., 2.5–5 U per 0.05–0.1 mL per injection point); distribute evenly across mapped area (typically 10–20 injections/axilla).
- Mapping:
- Perform Minor starch-iodine test to define hyperhidrotic area before injection for complete coverage (improves efficacy/durability) 3.
- Interval:
- Retreat when effect wanes; typical durability ~4–7 months; do not schedule earlier than clinical recurrence.
Evidence notes and strength
- Randomized side-by-side trial: 100 vs 200 U Dysport per axilla—equal efficacy; choose lower dose (100 U) to reduce exposure and cost; supports escalation only if short duration 1.
- Retrospective cohort (2001–2020): standard 150 U/axilla; first-cycle duration ≥6 months predicted fewer injections over 3 years (QOL benefit), informing step-up to 150 U for short responders 2.
- Broader syntheses confirm BoNT-A improves sweat reduction and QOL with mild, local AEs; technique affects outcomes 3, 4. These support use but do not specify Dysport dosing.
Pitfalls and how to avoid them
- Undercoverage of the sweating area leads to early recurrence: always map with starch-iodine and use multi-point intradermal blebs 3.
- Excess dose without added benefit: avoid 200 U/axilla; 100–150 U is sufficient in trials 1.
- Too-early retreatment: wait for clinical recurrence; typical 4–7 months to balance efficacy and minimize antibody risk (rare).
- Do not extrapolate pediatric spasticity Dysport labeling to hyperhidrosis; it is unrelated to intradermal dosing sites or outcomes 5.