You can use it if the acne lesions are active and responding to the application. However topical tretinoin is also effective on acne scars as well, its use should only be limited till the condition lasts. The moment lesions and scars have subsided should be discontinued due some adverse effects as redness, peeling and painful skin.
Next Steps
This topical application should be accompanied with other topical application's as well as face washes.
Health Tips
Do not use larger amount of cream for acne or overuse it beyond recommendation.