From LSWiki

Poison Resistance is DEAD! R.I.P. It isn't here anymore. Don't bother looking for it in-game.

Class: Resistance Skills
Attribute: Vitality
Pedagogy: Body Alteration
Practitioner Term: Practitioner of Poison Resistance

This skill represents the resistance of one's system to poisons.  In those without a natural resistance, it can be trained through
the introduction of very small doses so as to develop a tolerance.

Poison resistance can be increased by exposure to venom, changing more quickly according to one's somatic adaptability.  It will
decay over time, weakening more quickly according to one's somatic adaptability.

Trainers

Temple of Discordia: Erasmus
Temple of Aeda: Phyrra
Association:
Guild:
Quest: