Objective: To evaluate the efficacy of botulinum toxin type-A (BoNTA) for the treatment of inverse psoriasis.
Background: The use of BoNTA in inverse psoriasis would be a novel approach compared with conventional treatments and may act at the neuroglandular junction level to reduce local sweating with its consequent skin maceration and secondary infection and at the extra-junction level to inhibit the liberation of neuropeptides and other pro-algogenic substances responsible for inflammation, hyperkeratosis and pain transmission.
Patients: Fifteen patients with a confirmed diagnosis of inverse psoriasis were enrolled into the study. The psoriasis was located in several areas: armpits (7 patients), submammary sulcus (6 patients), intergluteal folds (7 patients), inguinal folds (5 patients) and umbilicus (1 patient).
Methods: BoNTA treatment comprised individual injections 2.8 cm apart of 2.4 U BoNTA, with a total dosage between 50 and 100 U per patient depending on the extent and severity of the psoriasis. Patient assessments were done pre-treatment and at 2, 4 and 12 weeks post-treatment. The erythematous area was defined using objective photographic evidence, and subjective patient assessment of pain and itch was assessed using a 10-point visual analogue scale scale.
Results: Subjective symptomatology improved in all patients and erythema extension, intensity and infiltration improved in 13 of 15 patients (87%). Treatment was well tolerated with no reported adverse events.
Conclusions: BoNTA therapy resulted in improvements in subjective patient symptomatology and objective reductions in erythema and maceration in the treated areas according to photographic evidence. Further large-scale methodologically rigorous studies are required to investigate the safety and efficacy of BoNTA in this indication.