Small red pimples on the penis skin may be related to vulvar eczema, candida prepuce and glans penis, infectious molluscum contagiosum and so on. 1. Vulvar eczema: affected by environmental factors and other external factors (such as contact with plant pollen, eggs, fish, shrimp, milk and other allergens) can induce this disease, erythema, pimples and other polymorphic damage, accompanied by intense itching, can involve the vulva and the surrounding skin. 2. Candida glans phimosis: glans phimosis is prone to occur in the circumcision, may be conscious of itching, burning sensation. Physical examination of the penis foreskin and glans can be seen flushing, pimples, there may be a little scaling or oozing. The long foreskin or poor hygiene and local dampness is the cause of this disease. 3. Molluscum contagiosum: It is a contagious skin disease caused by molluscum contagiosum virus infection. The skin lesions are characterized by waxy shiny papules or nodules, the tip of the depression, can squeeze out the cheese-like molluscum contagiosum. Mainly infected through direct contact, patients are often infected in public bathrooms or swimming pools, but also through sexual contact. Small red bumps on the skin of the penis may also have other causes, should promptly seek medical attention, follow the doctor’s instructions for further examination, with the help of the doctor to clarify the cause, targeted treatment or treatment.