If they don't come to a head, they are probably not pimples. You may be experiencing an allergic reaction to something, such as food or cleaning chemicals.  If this continues I would suggest you go to a dermatologist and have them take a look at it to see if there is a way to prevent it from happening again.

I started having problems with cysts when I started going through menopause about 5 years or so ago, I am now 53 and it has been a year since my last period.  I got them on my groin, underarms and chin.  I still get them once in awhile.   Some of them came to a head some didn't, I had to go on antibiotics for some of them  and had to go in for antibiotic shot every day for a week on a few of them.  I lost work due to a couple of them being so bad.  They were painful and very easily irritated.  I now have scars on my chin so I get ingrown hairs that are constant.  I am hoping I can eventually have a laser treatment or something to get rid of the scars and hairs. 

I can't complain to much, the cysts were the only problem I had through Menopause, a couple of hot flashes early on then nothing but cysts.  My periods were horriable so I was looking forward to it.