Another itchy condition, anogenital pruritus, also may arise from nerve pathology. In a study of 18 men and 2 women (mean age 53 years) with “idiopathic” anogenital pruritus, degenerative changes in the lower spine were found on x-ray in 16, and lumbosacral radiculopathy confirmed by nerve conduction studies in 16. Paravertebral injections of triamcinolone and lidocaine reduced the degree of pruritus and sleep disturbance but were less effective in reducing other symptoms such as burning, tingling, and pain (Am. J. Acad. Dermatol. 2005;52:61–6).
Finally, there are many references to conditions such as “neurotic excoriation,” “psychogenic pruritus,” “senile pruritus,” in the literature, all suggesting that the itch is in the patient's head. “You have to be careful about assuming people are crazy when they actually may have pathologic changes in the nervous system that are making them itch,” Dr. Bernhard said.
Localized pruritus of the midback occurs in about 10% of the population.
Patients who have brachioradial pruritus sometimes gouge their forearms to alleviate the sensation. Photos courtesy Dr. Jeffrey D. Bernhard