Some people are afraid of using sunblock as it may cause congestion and encourage more pimples to grow. However, any dermatologist would say that sunblock is a must in daily skincare routine, even if you have a tight budget. Acne prone skin should beware of UV rays as they can cause severe skin problems, as such a good sunblock is essential.
So, there are two factors to consider when we want to purchase a suitable sunblock: non comedogenic ingredients should be used and the sunblock should be light/oil-free.
Still, some people will experience the problem that pimples would grow aggressively after they apply the aforementioned sunblock. In this case, one should check their cosmetics (foundation) and cream based skin care products such as cleansing oil, moisturizer, nourishing mask, etc whether they contain comedogenic ingredients.