Hello. Without an exam, it would be hard to tel for sure what the cause of your skin condition is but, if I had to guess, I would say they are probably ingrown hairs caused by shaving with a dull or cheap razor or living in a warm/humid environment and wearing clothing that doesn't allow good air circulation. If you are quite overweight, it would have the same moisture-trapping effect to your warmest body areas.
Another thought...If these areas are itchy when the bumps develop, it may be caused by localized yeast infections. If this is the case, wearing loose clothing, using an ointment like miconozole (anti-fungal for athletes foot, jock itch, etc.), eliminating white flour and sugar from your diet and add yogurt to it, and watching for signs of other infections (e.g. staph-causes red/very painful area often with swelling and tiny water-filled blisters) would be therapeutic. I hope this helps! ~MM
From the symptoms it looks like irritated hair follicles after shaving rather than herpes which presents as painful, itchy blisters. Wear cotton clothes and apply warm compresses and topical antiseptics on the bumps. Then apply some topical antibiotics cream like Neosporin. Also use an antibacterial soap or mild soap like dove. Avoid any kind of cosmetics. In case the symptoms persist then oral antibiotics may be needed. Please consult a dermatologist in that case.
I hope it helps. Take care and please do keep us posted on how you are doing.