Does this look like necrosis? Sclerotherapy done a week and 4 days ago. What is the grey in the middle? Will it spread? (Photo)

2 weeks after the first session bruising disappeared. Now on the second session I developed these and they are still here a week and 4 days later . If it is necrosis can it spread and get bigger? Is there something I can to now to improve any scarring ? They look like burns to me.
