I agree with the answers by Dr Winston and Dr Israr. Intralesional injections are mainly recommended for acne cyst. As previously mentioned, frequent steroid injections can caused skin thinning and atrophy and if this happens it may be irreversible!
There are many other effective treatments to get the acne under control like oral antibiotics and isotretinoin. So speak to your dermatologist and tell her your concerns and discuss if these other options are suitable for you.