Isolated photon production in pp and p-Pb collisions at LHC with ALICE

Photons are unique probes to study QCD processes since they do not interact strongly. Isolated photon production in pp collisions is one of the most clear tests of hard QCD processes and nuclear parton distribution functions. Photon measurement in pA collisions provides the opportunity to measure initial geometrical scaling and possible modifications of the nucleon structure function in nuclei. The ALICE collaboration has collected data on pp and p--Pb collisions at several colliding energies. ALICE is able to measure isolated photons down to small $p_{\mathrm{T}} \sim$ 10 GeV/$c$, thus extending previous measurements down to small $x$. In this talk, the isolated photon distributions measured in pp and p--Pb collisions at $\sqrt{s}_{\mathrm{NN}}$ = 5.02 TeV will be presented.