Red dots like patches after microneedling. Is it normal for these red dots to show up and how long before they disappear?

After a micro needling treatment it is normal for the skin to be pink or even red like a sunburn, but this all depends on how aggressively the treatment was performed, i.e. how deep the needles are set, how many times the skin is passed over, etc.  Other patients walk out with just a hint of pink.  Usually this redness fades after 12-24 hours.  If you have sensitive skin, rosacea, underlying redness, or if the treatment was "aggressive," then more stubborn red dots can appear, as you say.  These should fade.  If you have any concerns, speak to your doctor.  Be well!

After a micro needling treatment it is common for the skin to be bright red like a sunburn.  This redness fades after twenty-four to forty-eight hours.  Occasionally areas treated more aggressively will have collections of holes or raw areas.  These collection of holes will look like red dots or occasionally scabs or even bruising.
You should be fine but if you have any concerns I recommend you return to your provider for evaluation and treatment if necessary.  Best, -Dr. Z.