  We analyze IceCube public data from its IC86 configuration, namely PSTracks
event selection, to search for pseudo-Dirac signatures in high-energy neutrinos
from astrophysical sources. Neutrino flux from astrophysical sources is reduced
in the pseudo-Dirac scenario due to conversion of active-to-sterile neutrinos
as compared to the neutrino oscillation scenario of only three active neutrinos
over astrophysical distances. We fit IceCube data using astrophysical flux
models for three point-like sources in both scenarios and constrain the
active-sterile mass-square-difference in the absence of any evidence for
pseudo-Dirac scenario. We find that a common mass-squared-difference $\delta
m^2$ for all three flavors can be constrained as $\delta m^2 \lesssim 2.2
\times 10^{-19} eV^2$ for the source NGC 1068, $\delta m^2 \lesssim 1.2 \times
10^{-20} eV^2$ for the source TXS 0506+056, and $\delta m^2 \lesssim 1.5 \times
10^{-21} eV^2$ for the source PKS 1424+240 at 90% C.L. A stacking analysis
gives a constraint on $\delta m^2 \lesssim 1.5 \times 10^{-21} eV^2$ at 90% CL
which is dominated by the constraint obtained from PKS 1424+240.
