A phase pulse fired from a MACO phase-pistol
Phase-pulse infection was a potentially fatal condition, the result of being shot with a phase-modulated energy weapon set to a high level. Andorians were particularly susceptible to phase-pulse infections. (ENT: "United")
In 2154, Lieutenant Talas, a member of the Andorian Imperial Guard under the command of Commander Shran, died of a phase-pulse infection, a result of being shot with a phase-pistol by a Tellarite named Naarg. Although Talas was only grazed, the pistol was set to kill, injuring her beyond Doctor Phlox's ability to treat. (ENT: "Babel One", "United")
In the final draft script of "United", phase-pulse infection was intended to be shown with "dark blue striations mark[ing] the pale blue skin of Talas' bare shoulder."