Fixing plasterboard near corner

[sasl]

I recently replaced a built-in wardrobe and whilst stripping out the stud wall that made up the old wardrobe I cut the plasterboard too far beyond the edge of the new wardrobe and now I have to repair it. I have a thin slither of plasterboard now missing along the whole edge of the wardrobe:

I'm wondering how best to repair the plasterboard. I've only ever repaired small holes and filled in old electrical boxes, nothing as large and near to a corner as this. I can think of a few different approaches. Probably the neatest would be to remove the whole plasterboard panel up to the corner and replace it with one long thin slither cut from a larger stock. Would I then have to install a mesh to protect the corner, and if so would that need then plastered in on both sides of the corner? That sounds like it could be a major piece of work but I guess should look best? Another approach could be to neaten the existing cut edge by making a new cut parallel to and a few cm right of the wardrobe trim, then replace with a new long thin piece wide enough to slot behind the trim. I fear it might be tricky to blend this in to the existing plasterboard and not end up seeing a seam there once finished.

Any advice appreciated!

 

[Wayners]

Remove that damaged plasterboard and replace.
Put a 3mm stop end bead up the front corner, and another against the shelf side panel and skim up the front edge with toupret powder filler.
Having 2 stop beads will make it easy to level as they will act as a guide. You just need a scraper blade wide enough to bridge the two stop end beads.

 

[RrogerD]

Or, squirt with expanding foam, let it set fully, scrape off the excess inc 2mm below surface and then use filler to bring to surface level.

 

[foxhole]

If everything is remaining white cut in a flat strip of UVPC trim to finish the edge.It will look like part of the wardrobe.