Agree with my colleagues who have all expertly answered your question.
I would like to point out that frequent intralesional steroid injections has an incremental risk of skin atrophy, steroid acne and even forming a sterile abscess. Therefore, the technique and dosage of steroid used (based on size of the cystic acne) is key to minimise the risk of above side effects.
When possible, prevention is key when it comes to treatment of acne; with a good cleanser for oil control and moisturiser- suitable for your skin type.
Hope this helps!
Cheers,
Dr David Deng