My boyfriend gets knot like places on his inner things. usually when they pop they're full of pus but occasionally they're full of just blood?

Infected follicles: he inner thigh usually in men with hair on their legs gets rubbed by pants etc. The follicles can get infected and develop pus in them and even blood in them. The key is to keep clean and put antibiotic oint on them when small. Make sure the pants are not too tight and monitor to make sure the area around is not getting red and infected when an oral antiobiotic is needed