Send to

Choose Destination
J Dermatol Sci. 2019 Jan;93(1):58-64. doi: 10.1016/j.jdermsci.2018.12.004. Epub 2018 Dec 28.

Botulinum toxin blocks mast cells and prevents rosacea like inflammation.

Author information

Department of Dermatology, University of California, San Diego, CA, USA.
School of Medicine, University of California, San Diego, CA, USA.
Department of Anesthesiology and Pharmacology, University of California, San Diego, CA, USA.
Department of Dermatology, University of California, San Diego, CA, USA. Electronic address:



Rosacea is a chronic inflammatory skin condition whose etiology has been linked to mast cells and the antimicrobial peptide cathelicidin LL-37. Individuals with refractory disease have demonstrated clinical benefit with periodic injections of onabotulinum toxin, but the mechanism of action is unknown.


To investigate the molecular mechanism by which botulinum toxin improves rosacea lesions.


Primary human and murine mast cells were pretreated with onabotulinum toxin A or B or control. Mast cell degranulation was evaluated by β-hexosaminidase activity. Expression of botulinum toxin receptor Sv2 was measured by qPCR. The presence of SNAP-25 and VAMP2 was established by immunofluorescence. In vivo rosacea model was established by intradermally injecting LL-37 with or without onabotulinum toxin A pretreatment. Mast cell degranulation was assessed in vivo by histologic counts. Rosacea biomarkers were analyzed by qPCR of mouse skin sections.


Onabotulinum toxin A and B inhibited compound 48/80-induced degranulation of both human and murine mast cells. Expression of Sv2 was established in mouse mast cells. Onabotulinum toxin A and B increased cleaved SNAP-25 and decreased VAMP2 staining in mast cells respectively. In mice, injection of onabotulinum toxin A significantly reduced LL-37-induced skin erythema, mast cell degranulation, and mRNA expression of rosacea biomarkers.


These findings suggest that onabotulinum toxin reduces rosacea-associated skin inflammation by directly inhibiting mast cell degranulation. Periodic applications of onabotulinum toxin may be an effective therapy for refractory rosacea and deserves further study.


Botox; Botulinum toxin; Mast cell; Mechanism of action; Rosacea

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center