Neuropathic scrotal pruritus: anogenital pruritus is a symptom of lumbosacral radiculopathy

Abstract

Background: Anogenital pruritus is defined as an itch localized to the anus, perianal, and genital skin. Anogenital pruritus is usually a symptom of an underlying disorder of the skin or mucosa or a consequence of anorectal pathology. When no demonstrable cause is found, anogenital pruritus is often described as "idiopathic".

Objective: To investigate the role of lumbosacral radiculopathy in the pathogenesis of anogenital pruritus.

Methods: Included in the study were consecutive patients with anogenital pruritus. Radiographs and nerved conduction studies were performed in all patients. Needle electromyography studies and computerized tomography were performed when necessary. Nerve conduction studies included measurement of distal sensory and motor latency, conduction velocity, and F-responses of the peroneal and tibial nerves. Patients with confirmed radiculopathy were treated with paravertebral injection of a mixture of triamcinolne acetonide and lidocaine. Response to the injections was assessed using visual analogue scales by the patients. Mean scores before and after treatment were compared using paired t tests.

Results: Included in the study were 20 patients with anogenital pruritus. There were 18 men (90%) and 2 (10%) women. The mean age was 52.7 years (standard deviation [SD] 11.7 years). In 16 patients (80%), radiographs demonstrated degenerative changes of the lower spine. In 16 patients (80%) the presence of lumbosacral radiculopathy was confirmed by nerve conduction studies. Fifteen patients (75%) were treated with paravertebral injections, with significant decrease in mean pruritus score as assessed by the patients (6.3 [+/-2.8]; 4.5 [+/-2.7], before and after treatment, respectively, P = .033).

Conclusion: "Idiopathic" anogenital pruritus may be attributable to lumbosacral radiculopathy. Paravertebral blockade may be used for alleviation of symptoms in patients with anogenital pruritus.