  In a recent PRL Barci and Stariolo (BS) generalized the well known Brazovskii
model to include an additional rotationally invariant quartic interaction and
study this model in two dimensions (2d). Depending on the parameters of the
model, BS find two transitions: a first order isotropic-lamellar (striped) or a
second order isotropic-nematic (which they speculate to be in the
Kosterlitz-Thouless universality class). Using a simple symmetry argument, I
show that the striped phase found by BS can not exist in 2d. Furthermore, I
argue that based on the coarse-grained action used by BS it is impossible to
reach any conclusion about the nature of the isotropic-nematic transition.
