GOTHENBURG, SWEDEN – Botulinum toxin injections to the soles of the feet are a highly effective, safe, and long-lasting treatment for painful blistering and calluses in patients with sweat-exacerbated epidermolytic keratinopathies, according to Dr. Anders Vahlquist said at the annual congress of the European Academy of Dermatology and Venereology.
The same technique is also beneficial in patients with acantholytic disorders aggravated by sweat and friction, such as the intertriginous erosive lesions of Hailey-Hailey disease or Darier disease, said Dr. Vahlquist at the annual congress of the European Academy of Dermatology and Venereology.
Dr. Vahlquist, a professor of dermatology at Uppsala (Sweden) University, and colleagues introduced plantar botulinum toxin injections as a novel treatment for sweat-exacerbated severe foot problems caused by epidermolytic keratinopathies more than 4 years (Br. J. Dermatol. 2006;154:763-5).
At the EADV congress, he presented his updated experience with the therapy in six patients with epidermolysis bullosa simplex and eight with pachyonychia congenita ranging in age from 7 to 66 years.
These were patients who had considerable difficulty in walking, especially during warm weather, because foot sweat worsened their plantar blistering at pressure sites, said Dr. Vahlquist. The patients received a mean of 5.6 treatment sessions, each entailing multiple injections of botulinum toxin type A or B to the soles of the feet administered under intravenous regional or general anesthesia.
Thirteen of the 14 patients reported what Dr. Vahlquist described as "remarkable" relief of pain within a week. The mean duration of benefit patients reported was 3 months. Because the foot symptoms were most problematic during the warm weather months, most patients did well with one or two treatment sessions per year. This is good news because the anesthesia requirement – essential because the soles are so sensitive – makes this an expensive therapy, he noted.
Seven of the eight patients with pachyonychia congenita and five of six with epidermolysis bullosa simplex rated their condition as either "very much" or "a lot" improved after treatment.
Dr. Vahlquist noted that physicians at Roger Williams Medical Center in Providence, R.I., have also reported that botulinum toxin injections to the soles of the feet are effective for patients with epidermolysis bullosa simplex (Arch. Dermatol. 2009;145:13-5).
"With this confirmatory study in the United States, we hope that this therapy will see greater use. It would be a help to many patients while we wait for the curative therapy that’s hopefully to come," he said.
Dr. Vahlquist said he has also used this therapy in 10 patients with Hailey-Hailey disease featuring sweat-exacerbated painful erosive lesions in the groin and other intertriginous areas. He termed the results of this chemical denervation of the sweat glands in the targeted areas "very promising."
A Swiss dermatologist from Bern rose from the audience to confirm the benefit of botulinum toxin in patients with Hailey-Hailey disease. He and his colleagues have treated a dozen such patients with what he described as "really impressive" outcomes. "The results are fantastic," he said. "These patients are born again. They are really very, very happy."
Dr. Vahlquist reporting having no relevant financial interests.