spiderbites man
brown recluseseses
If it was actually a Brown Recluse that bite him it would not just leave those tiny marks. A Brown Recluse spider bite is more than noticeable to say that least.
Bullstuff i've had a docter tell me they weren't cancerous when my family paid money for me to get a flu shot.
They may not be cancerous at the moment, but I would watch them. If they start to swell up you need to get them checked immediately.
But anyway. I would say you have something called a Pigment Spot. A pigment spot usually occurs after an acne spot has disappeared, as you said. The cause for this spot is something called Melanin, a chemical produced naturally in the body. An acne spot is essentially an infection. Due this this infection the body will produce this chemical. If it produces to much Melanin it can cause these brown spots to appear. This entire process is called 'post-inflammatory hyperpigmentation' and it is the #1 cause of these brown spot.
Essentially the spots should disappear in a matter of weeks on their own. If they don't you can probably get some cream at a pharmacy.