There are many possible causes of small grains of flesh on the nipples of boys, as follows: 1. Acne. The hair follicles there are clogged, resulting in dermatitis caused by the inability of the sebaceous glands to excrete. You can use Bactrim ointment to apply, if necessary, oral anti-inflammatory treatment. 2, nipple injury. It is possible that the nipples are damaged because of too much rubbing, and accompanied by inflammatory skin growth, you can ensure that the nipples are clean, do not massage, apply erythromycin ointment, while replacing loose and comfortable bras. 3, the nipples are allergic to the formation of pimples. When exposed to poor quality bras or poor quality body milk, resulting in nipple allergy, manifested as nipple pain, itching and nipple pimples, you need to find out the allergic substances and stay away, while actively carrying out drug anti-allergy treatment. 4, sebaceous cysts. Insufficient nipple cleaning, sebaceous secretions gather, leading to cysts in severe cases, which need to be surgically removed.