The main reasons for this are: 1, the bumps are pinpoint size and thread-like, consider filiform warts; 2, the bumps are bag-shaped, there is a tip link between the bumps and normal skin, the color and normal skin color, touch is soft, and there is no feeling with hand squeeze and tug bumps, consider is sarcoid also called soft tissue fibroids; 3, the bumps are semi-circular, and normal skin color or brown, the surface is smooth, no pain, no itch. The above three are viral infections resulting in contagious and self-inoculation, so the patient towels should be used separately from others to prevent infection, usually do not use their hands to buckle, scratch the affected area, otherwise the number of bumps will increase, to the hospital with laser, freezing to remove; 4, the neck bacterial infection, resulting in inflammation of the hair follicles will appear red bumps, some will be accompanied by itching, painful symptoms.