The itching plague was one of the more unique problems affecting the Vongforming of Yuuzhan'tar after the Yuuzhan Vong conquered the planet Coruscant.
A fungus released by the World Brain, the plague caused massive, persistent itching. Though the Yuuzhan Vong theoretically should have been able to simply ignore it, a number of high ranking members of the Elite succumbed to the stress of the fungi rather easily. The release of the plague was also inauspicious—it was first discovered the day Supreme Overlord Shimrra arrived on Yuuzhan'tar. Eventually, Master Shaper Nen Yim was able to develop an anti-fungal balm, but it would only kill the fungi on contact and it was still possible to be re-infected. The plague was still present even as of 29 ABY, two years after it was first released.