Neurologic Itch Management

Neurologic itch is defined as pruritus resulting from any dysfunction of the nervous system. Itch arising due to a neuroanatomic pathology is seen to be neuropathic. Causes of neuropathic itch range from localized entrapment of a peripheral nerve to generalized degeneration of small nerve fibers. Antipruritic medications commonly used for other types of itch such as antihistamines and corticosteroids lack efficacy in neuropathic itch. Currently there are no therapeutic options that offer relief in all types of neuropathic pruritus, and treatment strategies vary according to etiology. It is best to decide on the appropriate tests and procedures in collaboration with a neurologist during the initial work-up. Treatment of neuropathic itch includes general antipruritic measures, local or systemic pharmacotherapy, various physical modalities, and surgery. Surgical intervention is the obvious choice of therapy in cases of spinal or cerebral mass, abscess, or hemorrhagic stroke, and may provide decompression in entrapment neuropathies. Symptomatic treatment is needed in the vast majority of patients. General antipruritic measures should be encouraged. Local treatment agents with at least some antipruritic effect include capsaicin, local anesthetics, doxepin, tacrolimus, and botulinum toxin A. Current systemic therapy relies on anticonvulsants such as gabapentin and pregabalin. Phototherapy, transcutaneous electrical nerve stimulation, and physical therapy have also been of value in selected cases. Among the avenues to be explored are transcranial magnetic stimulation of the brain, new topical cannabinoid receptor agonists, various modes of acupuncture, a holistic approach with healing touch, and cell transplantation to the spinal cord.