However the beneficial effects of botulinum toxin A on other diseases causing pruritus and pain has previously been reported. Botulinum toxin A has been shown to prevent the release of substance P, a well known mediator involved in pain and itch, and this may explain its efficacy in pruritic diseases. This proposal plans to study the efficacy and safety of botulinum toxin A (Xeomin) for the treatment of notalgia paresthetica in a randomized placebo controlled trial. Botulinum toxin A prevents the release of neuromediators such as acetylcholine. Botulinum toxin A has been used for many years to treat various disorders including blepharospasm, spasmodic torticollis, post stroke spasticity of the upper limbs, strabismus, palmar and axillary hyperhidrosis and wrinkles. This study will use Xeomin, a purified botulinum clostridium neurotoxin A that has recently been approved by Health Canada. Xeomin is currently approved for the treatment of blepharospasm, spasmodic torticollis and post stroke spasticity of the upper limbs.