Anosmia (3.5e Trait)
From D&D Wiki
Your character lacks any sense of smell, but her/his other senses pick up the slack
Prerequisite: Cannot have the Heightened Smell Trait.
Drawback: Your character gets -2 on Survival checks and automatically fails any checks to notice to smells.
Special: Gnomes with this trait loose their racial bonus to Alchemy checks, but get an additional +1 to Spot checks.
Roleplaying Ideas: The character may get tetchy when a team mate mentions something smells nice.