Sun exposure is a well-known flare for many rosacea sufferers. Sun protection using a wide-brimmed hat (at least 6 inches) and physical sunscreens (like zinc or titanium) are generally encouraged. Because rosacea tends to occur in mostly fair-skinned adults, physicians recommend the use of an appropriate daily SPF 50 sunscreen lotion, along with overall sun avoidance.
It's a myth that tanning clears up your skin. UV rays put you at risk for skin cancer, premature aging, and wrinkles. Don't lie in the sun or use a tanning booth. Also, some commonly prescribed acne medications, including retinoids that go on your skin, can make you more sensitive to damage from UV rays. So always wear sunscreen and limit how much sun you get.
No one factor causes acne. Acne occurs when sebaceous (oil) glands attached to the hair follicles are stimulated at the time of puberty or due to other hormonal changes. Sebum (oil) is a natural substance that lubricates and protects the skin. Associated with increased oil production is a change in the manner in which the skin cells mature, predisposing them to plug the follicular pore. The plug can appear as a whitehead if it is covered by a thin layer of skin, or if exposed to the air, the darker exposed portion of the plug is called a "blackhead." The plugged hair follicle gradually enlarges, producing a bump. As the follicle enlarges, the wall may rupture, allowing irritating substances and normal skin bacteria access into the deeper layers of the skin, ultimately producing inflammation. Inflammation near the skin's surface produces a pustule; deeper inflammation results in a papule (pimple); if the inflammation is deeper still, it forms a cyst.