I have tennis elbow which i have had 3 cortisone injection now my elbow look a red and purple in colour the last injection was in september last year?

Local reaction: The skin and overlying tissues can be altered by the steroid injection. There is sometimes a thinning of the skin and a loss of the subcutaneous (under the skin) fat that renders the appearance reddish purple. It may improve over time. I would limit injections to no more than three. If the tennis elbow returns, consider surgery. Before that, identify the cause and avoid the activity or wear brace.