regex - Regular expression to remove commas after the first -

i have file looks like:

16262|john, doe|john|doe|jd|etc... 

i need find , replace cases as:

16262|john, doe, dae|john|doe dae|jd|etc... 

by

16262|john, doe dae|john|doe dae|jd|etc... 

in summary, want alter in second field commas after first (may more 1 after).

any suggestion?

with gnu sed:

bre syntax:

sed 's/\(\(^\||\)[^|,]*,\) \?\|, \?/\1 /g;' 

ere syntax:

sed -r 's/((^|\|)[^|,]*,) ?|, ?/\1 /g;' 

details:

(          # group 1: begining of item until first comma     (      # group 2:         ^  # start of line       |    # or         \| # delimiter     )     [^|,]* # start of item until | or ,     ,      # first comma )          # close capture group 1 [ ]?       # optional space |        # or   ,          # other comma [ ]? 

when first branch succeeds, first comma captured in group 1 begining of item, since replacement string contains reference capture group 1 (\1), first comma stay unchanged.

when second branch succeeds group 1 not defined , reference \1 in replacement string empty string. why other commas removed.