hi..Thanks for your query.
The pattern of eruptions you describe,may be acne vulgaris
This presents in several forms and the treatment depends on the kind of lesions you are having.The common areas where one can have acne are face, chest,back, upper arms.
You can start using a mild retinoid
cream on alternate nights and a clindamycin
gel in the morning to treat the ongoing eruptions.You should visit a dermatologist
soon to get started on oral therapies.Acne if treated early , will be easier to control.However , if left untreated, may lead to post inflammatory hyper pigmented as well as atrophic scars
Hope this helps!Take care.