Botulinum Toxin Shows Promise for Psoriasis

Close up of nurse preparing a syringe for an injection
The effect of botulinum neurotoxins (BoNT-A) on the change of total clinical score of skin lesions of patients with plaque psoriasis at week 4 was evaluated.

Patients with psoriasis experienced significant improvement in their total clinical score (TCS) 4 weeks after treatment with botulinum toxin, according to findings from a small study published in Dermatologic Therapy.

Researchers conducted a proof-of-concept study of botulinum toxin in 8 patients with stable plaque psoriasis and some lesions recalcitrant to therapy (6 patients were on topical therapy only and 2 patients were on biologic therapy). For each patient, the investigators selected up to 2 plaques, with a maximum diameter of 5 cm2. Participants received a single botulinum neurotoxin A (BoNT-A) injection at a dilution of 5 units per cm2, with a maximum of 50 units. A clinical evaluation, measurement of TCS, and a photographic record were performed at weeks 0, 2, and 4 after the BoNT-A treatment.

The mean age of the patients was 50.75 years (range, 30-62 years), the majority were White (62.5%), and the initial average TCS was 8 (range, 6-11) (P = .590). At 4 weeks, the TCS score was 4.92 (range, 3-8) (P = .557), a difference of 3.083 points (P = .001), demonstrating a statistically significant clinical improvement.

All parameters that were evaluated—desquamation, erythema, and infiltration—for the TCS score showed improvement, but especially noteworthy was improvement in erythema and infiltration of the evaluated lesions, according to the study authors, and 2 patients reported a significant decrease in the pruritus associated with their psoriasis lesions.

No serious adverse events occurred, and no adverse events directly related to BoNT were reported, the researchers wrote. In addition, none of the participants discontinued their participation during the observation period. “Our results indicated a substantial improvement in all patients, 4 weeks after treatment, with no significant side effects,” stated the researchers.

“Our study showed a significant improvement of 38.5% of mean difference (P = .001) of the TCS score following a single dose of BoNT, documented by photographic evaluation,” the investigators commented. “These results are concordant with other studies that have shown an improvement of psoriasis plaques following BoNT injections. This improvement in recalcitrant psoriasis lesions with a single application of a product with a high safety profile proposes a novel target in psoriasis treatment.” Large controlled trials are needed to further assess this potential treatment for recalcitrant plaques of psoriasis, they concluded.


González C, Franco M, Londoño A, Valenzuela F. Breaking paradigms in the treatment of psoriasis: Use of botulinum toxin for the treatment of plaque psoriasis [published online September 19, 2020]. Dermatol Ther. doi: