All four of my children get bumps from Johnson and Johnson baby products. I switched to organic hypo allergenic shampoo, and organic coconut oil for moisturizer.
You can't really prevent it and it has nothing to do with bad hygiene, it's basically from the babies oil glands over producing which is normal not all babies get it but a lot do and as the weeks go by they should disappear. They tend to clear up within 6 weeks but can last slightly longer.
When all babies are bofn they have this little bumps on their skin, my mom told me is from the amniotic fluid and it goes away eventually just put baby lotion on their skin everyday and on their head clean the grease they have with baby oil. I washed all the clothes with my first and she had the same problem but it was only for that first week