Blackheads and whiteheads both represent "clogged pores" meaning there is a collection of material within the duct of the sebaceous (oil) gland. They both represent types of comedones, which is a variety of acne
. The difference between blackheads and whiteheads is only that blackheads are open to are, which allows the contents of the pore to become oxidized and darken. Whiteheads contain the same material as blackheads, however because they are closed their contents cannot become oxidized and they remain white or skin colored. For this reason blackheads are called "open comedones" and whiteheads are "closed comedones."
The best way to keep your son's skin clear is for him to wash it regularly (once or twice a day) with a non foaming face wash. Foaming face washes can be overly-drying, which causes your skin to produce more oil and makes you more likely to develop clogged pores. After he washes his face he should dry it well and apply an oil free moisturizer. All of the products he uses should be labeled oil free and "non-comedogenic" which means they will not cause comedones. He may also use products with alpha hydroxy acids to help his skin shed dead skin cells so they will not build up and collect in pores, as this can worsen acne. Please call his primary care physician
if you would like help treating his acne, or if he has any skin lesions that concern you to make sure he does not have any more serious medical problems.