Welcome to HealthcareMagic. It can be due to boils
or cysts. Apply warm compresses and some topical antiseptics. Also wear loose-fitting cotton clothing and use an antibacterial soap
or mild soap like dove. You can also apply topical antibiotic
creams. However if the symptoms persist then oral antibiotics
may be needed. You have to consult your dermatologist then.
Hope it helps you. Regards.