Your body has a natural exfoliation process when it comes to skin cells, shedding old ones so that newer, healthier cells can take their place. When dead skin cells get trapped, they form small white cysts under the surface of the skin which are known as milia.   In addition to the improper shedding of dead skin cells, milia can be caused by:   ● Damaged skin from an injury. ● Damaged skin from sun exposure. ● Prolonged use of ointments and/or steroid creams. ● Certain genetic conditions condition. ● An autoimmune response.   Your healthcare provider or dermatologist can diagnose milia after performing a thorough examination. This is typically a visual exam of the cysts on your skin, which is an effective form of identification and diagnosis. If your provider needs more insight into the health of your skin, they may require you to undergo further testing.