Cholinergic Blockade · Axillary & Palmar · CityLink Mall
Excessive sweating is not a problem of too many sweat glands — it is a problem of glands being told to work too hard. Botulinum toxin interrupts that instruction at the nerve ending, which is why it reduces sweating in a defined area without removing anything or altering the skin.
Eccrine sweat glands are controlled by the sympathetic nervous system, but they are supplied by the one set of sympathetic fibres that uses acetylcholine rather than noradrenaline as its messenger. That anatomical oddity is the entire basis of the treatment. Botulinum toxin works by preventing acetylcholine release at nerve terminals — which is why it relaxes muscle — and it therefore works equally well on the cholinergic fibres supplying sweat glands. The signal to sweat is generated centrally as it always was. It simply stops being delivered.
The glands themselves are left intact. Nothing is destroyed, ablated or removed, and the skin over the treated area is unchanged. This matters for two reasons. It means the treatment is fully reversible, since function returns as the nerve terminals regenerate. It also means there is no scarring, no thinning and no permanent alteration to the area — which compares favourably with surgical approaches that remove glandular tissue or divide sympathetic nerves, both of which carry consequences that cannot be undone.
Delivery is intradermal rather than deep, because the glands sit in the dermis and at the dermal-subcutaneous junction. A grid of small injections is placed across the mapped area, spaced closely enough that the diffusion fields overlap and no untreated island is left behind. Mapping is done properly — in the axilla, a starch-iodine test can be used to stain the actively sweating zone, which is often larger or differently shaped than the hair-bearing area patients assume defines it.
Onset is not immediate. Existing acetylcholine already released continues to act, and the reduction in sweating becomes apparent over three to seven days, reaching full effect at around two weeks. The effect lasts as long as it takes for new axonal sprouts to re-establish transmission — commonly four to nine months in the axilla, and generally a shorter interval on the palms, where the density of glands is higher and the tissue is constantly in use.
Assessment
Before anything is injected, the question is whether this is primary focal hyperhidrosis or sweating caused by something else. The distinction is made from the history in most cases and it changes the plan completely — treating a secondary cause with toxin suppresses a symptom while leaving its cause unexamined.
Nothing is removed and nothing is destroyed. The gland is simply never told to switch on, and it starts again when the nerve does.
Realistic Expectations
Sweating does not switch back on. As nerve terminals regenerate, they do so unevenly, and patients usually describe the return as a gradual creep — sweating noticed first in a small area, then over a larger one, over several weeks. Most people recognise the point at which they want re-treatment well before the effect has gone entirely. Planning the next session around that pattern, rather than waiting for a complete return, tends to keep control more consistent, and many patients time it around a season or a work commitment.
Coverage is worth being precise about. The treated field stops sweating; skin outside it does not, and compensatory sweating elsewhere is occasionally reported although it is far less of an issue than with surgical sympathectomy. Palmar treatment is more demanding than axillary — it hurts considerably more, requires proper anaesthesia, and carries a small risk of temporary weakness in the small muscles of the hand if toxin reaches them, which matters to anyone whose work depends on fine grip. That risk is discussed before the palms are treated, not afterwards.
Toxin is not the only option and it is not always the first one. Topical aluminium chloride preparations, used correctly at night on dry skin, help a proportion of patients with axillary sweating and cost little to try. Oral anticholinergics have a role in some cases, and the same toxin is used elsewhere in the face for entirely different indications. Energy-based destruction of axillary glands is available and is more durable but is not reversible. Where sweating has caused darkening or irritation of the underarm skin, that is treated as a separate problem, since reducing sweat does not clear pigment already present.
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Atelier Aesthetics · Owned by AYA
1 Raffles Link, #B1-28, CityLink Mall, Singapore 039393 · +65 8023 7170
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