There is no spread or other visible marks surrounding the bed, but these white spots are scattered around most of the frame.
Is it mould?
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Not likely, mold needs the correct conditions to grow, and metal is not generally a porous enough surface to support growth. That looks like an aluminum frame, so I would guess that is oxidation popping through the paint.
If you believe it is still mold I would refer to this CDC article on mold.
Either way, you can wash it with a mild detergent and water, if it is mold, this should kill it. You can find a lot of references to using bleach for mold, but this if often more hazardous than the mold and should not be used