White raised bumps that are on the legs are a symptom of keratosis pilaris, as reported by Dr. Amy Forman Taub at Advanced Dermatology. The white raised bumps are benign, are not life-threatening and affect as much as 40 percent of the population. Keratosis pilaris is caused by a buildup of keratin, which is a protein found in the outer layer of the skin that causes the skin to thicken, underneath the hair follicles.
Individuals may inherit the tendency to develop keratosis pilaris from their parents. This condition has also been associated with dry skin conditions, like eczema. Keratosis pilaris can affect all individuals; however, it is typically most prominent in females, children and people with Celtic origins, as stated by the NHS.
Keratosis pilaris cannot be easily treated; however, it can be prevented by exfoliating regularly using exfoliating foam pads or pumice stones, using warm water rather than hot water when showering and bathing, using a moisturizing cream or ointment suited to skin type in order to moisturize the skin whenever it becomes dry and switching to non-soap cleansers rather than soap since soap can easily dry out the skin.
While keratosis pilaris is typically most prominent on the legs, arms, buttocks and upper back, this condition may also affect the facial regions in rare cases.