Hi,
If the keloids are on the scalp and treated with intralesional steroids, potential side effects include localized atrophy over the site of injection and infection. These side effects may be minimized by administering the appropriate amount and dose of steroid, good injection technique and ensuring that the treatment is performed in an aseptic setting.
If the keloids are not located on the scalp, then treatment with intralesional steroids will have no distant side-effects on the scalp.
Hope this helps!