Have stubborn psoriasis plaques that never seem to go away? Researchers investigating the effects of nerve damage have found that deliberately damaging the sensory nerves under psoriasis lesions can help.
Nicole L. Ward, associate professor of dermatology at Case Western Reserve University, and Dr. Erin Gilbert, assistant professor of dermatology at SUNY Downstate Medical Center, have discovered that directly injecting a neurotoxin similar to Botox into psoriasis lesions can reduce the inflammation that leads to plaque formation.
"We are injecting neurotoxin into the plaque itself, where it blocks sensory nerves," said Ward, who has won numerous research grants from the National Psoriasis Foundation.
She and Gilbert believe that the toxin prevents the release of specific proteins that play a critical role in skin inflammation. "By inhibiting the release of these molecules, the neurotoxin disrupts the inflammatory cascade in psoriasis, leading to an improvement in the disease," Gilbert said.
Researchers and clinicians had already observed that psoriasis lesions cleared up in patients who experienced nerve damage, such as from injury or surgery. Hearing about these cases, Gilbert said, "sparked our imagination." She and Ward decided to see whether causing deliberate nerve damage would have the same effect.
They first tested the procedure by surgically damaging the skin nerves of mice genetically altered to have psoriasis. This resulted in a significant improvement in the psoriasis —including a 30 percent decrease in skin thickening. The researchers then injected the mice's psoriasis lesions with abobotulinum toxin A, a neurotoxin known as Dysport that is similar to Botox. Again, the mice's psoriasis improved, showing a 25 percent decrease in skin thickening after six weeks.
Encouraged by these findings, the researchers then investigated whether Dysport injections could help people who have psoriasis. One of Gilbert's patients showed dramatic improvement following the treatment. "I injected her psoriasis plaque once with Dysport, and within a month she had less itching and the plaque had resolved," said Gilbert, adding that the lesion did not reappear for seven months.
The researchers are currently looking deeper into the effects of neurotoxins on mice, and hope to launch a clinical trial to further test the therapeutic potential of neurotoxins. "We are still in the early stages, and need to see if more patients respond in a similar manner," Gilbert said.
Ultimately, the researchers hope that Dysport or other neurotoxins could be used in conjunction with current treatments to clear particularly stubborn plaques.