Amelioration of body odor after intracutaneous axillary injection of botulinum toxin A.

BACKGROUND Body odor is a ubiquitous phenomenon. It is commonly attributed to sweating and noted explicitly in the axillary area. Botulinum toxin A has recently been shown to be effective for axillary hyperhidrosis. Its effect on axillary odor, however, is unknown. OBSERVATIONS Sixteen healthy volunteers were injected with botulinum toxin A (Dysport, 100 U dissolved in 0.9% sodium chloride solution) in one axilla and 0.9% sodium chloride solution in the other axilla in a randomized, double-blinded fashion. After 7 days, body odor was assessed by a T-shirt sniff test. A significant reduction of odor intensity was observed for the botulinum toxin A-treated side. The smell was also rated significantly less unpleasant. CONCLUSIONS These findings suggest that botulinum toxin A can ameliorate or even improve body odor. The underlying mechanisms may include interference with skin microbes and denervation of apoeccrine sweat glands, but this remains to be further investigated.