I have white bumps on my armpits after being in the pool 48 hours after laser hair removal.

Yes, if the bumps are small and not flat spots, it is likely due to irritation from activities like hair removal, chlorine, or sun exposure. You can try using a fragrance-free cream to hydrate the skin, which should help them disappear in a few days. If there appears to be pus, you can cleanse the area with mild soap and water, then apply some antibiotic cream that can be found at a pharmacy. In most cases, the bumps should go away quickly. If the situation worsens, it's a good idea to seek further advice.