``It's a very unpleasant way to die,'' said Dr. Philip Mackowiak, the director of the Historical Clinicopathological Conference at the University of Maryland medical school.
At the annual conference, doctors apply their diagnostic skills to historical figures whose deaths have not been satisfactorily explained. Previous conferences concluded rabies killed Edgar Allan Poe and that the Roman emperor Claudius died from eating poisonous mushrooms.
Before his death in 4 B.C., Herod suffered an array of symptoms - intense itching, painful intestinal problems, breathlessness, fever, swelling in the feet, convulsions and, finally, gangrene of the genitalia.
Peter Richardson, a religion professor at the University of Toronto, found the description of Herod's ailments in the writings of the first-century historian Flavius Josephus.
Fournier's gangrene, rare today, probably killed Herod, said Dr. Jan Hirschmann of the University of Washington medical school, who examined Herod's case history. The disease would have killed the king in a week or less.
Many have speculated that Herod had gonorrhea, but Hirschmann said there's no evidence to support that. Debunking such popular theories is the point of an intensive, clinical approach to Herod's death, Mackowiak said.
Kidney disease may also explain some of Herod's brutal acts - including the executions of several family members. The untreated accumulation of bodily wastes can result in mental illness.
``He had some mental changes - depression and a suicide attempt, as well as paranoia,'' Hirschmann said. ``These may be part of the disease, or they may be extensions of what he was like before.''
According to religious tradition, Herod, fearing the coming of a Messiah after Jesus' birth, ordered the execution of infant boys in Bethlehem, forcing Mary, Joseph and the child to flee to Egypt.