Excerpts from GURPS Egypt
Rotting Touch Advantage – 28 points (from p. 80)
This advantage allows an undead creature to inflict a flesh-destroying disease on the living by touch. The victim may avoid the effects by making an HT roll, but if this fails, the rot inflicts a point of damage, the affected flesh turning gray, becoming mushy, and rubbing away. Every 24 hours until dead, the victim loses another point of HT (if he fails an HT roll), unless he has a critical success on one of his HT rolls (which halts the progression of the rot) or someone cures the condition magically or surgically.
Up to an hour after the Rotting Touch attack, the victim may excise the rotted flesh, suffering 1d-2 points damage. Someone making a successful First Aid roll can remove the infected tissue without causing additional damage. After the initial hour, only amputation or surgery can medically arrest the decay, and trained surgeons willing to perform such operations are rare in Egypt (see Medicine, p. 7).