  We study the influence of short-range electron-electron interactions on
scaling behavior near the integer quantum Hall plateau transitions. Short-range
interactions are known to be irrelevant at the renormalization group fixed
point which represents the transition in the non-interacting system. We find,
nevertheless, that transport properties change discontinuously when
interactions are introduced. Most importantly, in the thermodynamic limit the
conductivity at finite temperature is zero without interactions, but non-zero
in the presence of arbitrarily weak interactions. In addition, scaling as a
function of frequency, $\omega$, and temperature, $T$, is determined by the
scaling variable $\omega/T^p$ (where $p$ is the exponent for the temperature
dependence of the inelastic scattering rate) and not by $\omega/T$, as it would
be at a conventional quantum phase transition described by an interacting fixed
point. We express the inelastic exponent, $p$, and the thermal exponent, $z_T$,
in terms of the scaling dimension, $-\alpha < 0$, of the interaction strength
and the dynamical exponent $z$ (which has the value $z=2$), obtaining
$p=1+2\alpha/z$ and $z_T=2/p$.
