We study a subset of the one-loop modifications of Higgs decay which effectively arises from four-quark operators involving top quarks. This effect is naively suppressed and small, but there can exist extra enhancement as large as $y_t/y_b$ or $y_t/y_\tau$. Corresponding effects on top productions are chiral suppressed. We concentrate on models with an extra scalar doublet, and investigate when this effect becomes primarily important and relevant to LHC Higgs phenomena. We find that $h \to \tau \tau$ mode can be sensitive to this effect.
