Medical pearl: the ice-pack sign in brachioradial pruritus.

P atients with brachioradial pruritus (BRP) often report that their itch feels ‘‘deep,’’ that scratching only makes it worse, and that the only thing that provides any relief is the application of ice packs, chilling the skin to the point of numbness. The ice-pack sign is nearly pathognomonic for this condition. The weight of available evidence suggests that BRP is a neurogenic/neuropathic itch. It usually presents with a picking, prickling, burning, or just plain itchy itch of one or both forearms. BRP can involve, or ‘‘spread,’’ to the upper arms as well (especially the lateral aspects). It occasionally spreads across the upper back, and very occasionally across the neck and uppermost chest. In some patients, sunlight acts as a trigger. Despite offering temporary relief, it is also possible that ice-pack application may be counterproductive, but this remains to be determined. There are anecdotal reports that treatment with oral gabapentin may be helpful in treating some patients with severe BRP.