Tried separately on 2 quarter sized dark spots on my forearms. Left on for 24...

Tried separately on 2 quarter sized dark spots on my forearms. Left on for 24 hours. Left very red marks for a week, so did not apply again. Then "hard" like a scab for the next week, but did not peel. After applying cream, now soft, but no lighter. But then, only used once given reaction.