Does getting an ear piercing with a needle reduce the risk for keloids when compared to a gun?

No: There is no way predicting which method of ear piercing will give you keloid.We know that keloids are more common in dark skin people.

Probably equal risk: If a patient has a keloid tendancy, it probably doesn't matter which method of piercing is used, the risk should be the same.

Comparable: The risk of forming a keloid has more to do with your propensity to form a keloid than the type of needle used. Both techniques use needles and traumatize the skin in similar manners so the risk should be about the same.

Both use a needle: so they are comparable.