  We consider a sequence of blowup solutions of a two dimensional, second order
elliptic equation with exponential nonlinearity and singular data. This
equation has a rich background in physics and geometry. In a work of
Bartolucci-Chen-Lin-Tarantello it is proved that the profile of the solutions
differs from global solutions of a Liouville type equation only by a uniformly
bounded term. The present paper improves their result and establishes an
expansion of the solutions near the blowup points with a sharp error estimate.
