Hard bumps protruding from the skin of the testicles may be the result of sebaceous adenomas or folliculitis, or they may be caused by eczema. 1. Sebaceous adenoma: Due to the blockage of hair follicles, the secretion of sebaceous glands is hindered, and the secretion gathers in the hair follicle area, forming white or flesh-colored hard bumps in the long run, usually in different shapes and sizes, and sebaceous adenomas are formed in the long term accumulation. 2. Folliculitis: The opening of the hair follicle is blocked when inflammation occurs, and the secretion accumulates in the hair follicle, the hair follicle will gradually become bigger and bigger, and then it will turn into a lump like a pimple. 3. Eczema: If you are in a humid environment for a long time, you may have scrotal eczema, which usually occurs in patches, and the pimples are often itchy, red, painful and swollen. Testicular skin raised hard bumps may also be skin flora, if accompanied by other discomforts, such as swelling and pain and other serious phenomena, it is recommended that patients go to the hospital in time for examination, to identify the cause of the disease after treatment.