Sebum production after botulinum toxin A (Botox, Allergan) treatment for forehead rhytids positively correlates with the distance away from the injection point, according to a new study. Intramuscular botulinum type A injections notably reduce sebum production at injection sites, while increasing sebum production of the surrounding skin, according to the study published May in the Aesthetic Surgery Journal.
Chinese and Italian researchers studied 42 females receiving intramuscular botulinum toxin A injections for forehead rhytides, looking for sebum regulation and gradient surrounding injection sites. They compared two injection doses — two and four units — administered in five standard injection sites, and measured sebum production at baseline and post-treatment.
Researchers found botulinum toxin A treatment resulted in significant change to the sebum at the injection site of both groups, with a sebum gradient surrounding the injection point.
“The efficacy did not improve at higher injection doses, with the four-unit regimen generally not being more potent than the two-unit regimen,” they write.
Sebum production, however, went back to normal levels at the 16-week follow-up for both treatment groups. This suggests the higher four-unit dosage did not result in a longer duration until relapse than the two-unit dose. While sebum production was lower at the injection sites, it increased at a radius of 2.5 cm at the 2-, 4- and 8-week follow-ups, the researchers write.
Implications for Practice
What implication does this study have for practice? Plastic surgeon Robert Singer, M.D., of La Jolla, Calif., who was not an author of the study says questions remain and more research is needed. The finding that Botox decreases sebum production is not new and has been in the medical literature for years, he says.
“What the implications will be in the practical use, we’ll have to wait and see. It may play a role in some patients with recalcitrant acne, but, at this point, there are a lot of other modalities of treatment, topically, that may be effective,” Dr. Singer says. “[Botulinum toxin A] certainly has not been studied in teens, who have most of the acne. It’s an interesting finding. I wouldn’t think it’s going to play a main role in treatment right now.”
The fact that the neurotoxin also increased sebum production leads to more questions, according to the plastic surgeon.
“Are you just shifting the area of sebum production and potentially the acne?” wonders Dr. Singer.
However, these findings could suggest that botulinum toxin A might be a potential acne treatment down the road, he says.
Min P, Xi W, Grassetti L, et al. Sebum production alteration after botulinum toxin type A injections for the treatment of forehead rhytides: A prospective randomized double-blind dose-comparative clinical investigation. Aesthet Surg J. 2015 Mar 29.