Hello,
Without examination,confirmation of a diagnosis is tough but it can be folliculitis, sebaceous cysts ,molluscum contagiosum(multiple, small, dome-shaped papules, often with a central depression or plug) or genital warts(caused by HPV infection).From the pictures they look like sebaceous cyst however.
Apply warm compresses,Neosporin ointment and calamine lotion and avoid messing with it.You can take anti-inflammatory pain killers like ibuprofen or acetaminophen.If the lumps persists then it will be best to get it evaluated from a dermatologist.
Hope it helps.If you have any additional queries,then pls post us.
Take care and regards.
It looks like seborrheic keratosis. If so, it is not dangerous.