High levels of iodine have been shown to illicit what are called acneiform eruptions. These eruptions are different from run-of-the-mill acne and are evidenced by a quick onset, wide distribution on the body, and pustule-only outbreaks . Whether smaller levels of iodine affect acne is unknown. According to an overview of the latest evidence regarding diet and acne published in the Journal of the American Academy of Dermatology , "Iodine has been implicated as a cause of acne vulgaris, however, no literature to date supports iodine as a culprit in comedonal acne." 1
Acne is a disorder that affects the skin’s oil glands and hair follicles. The small holes in your skin (pores) connect to oil glands under the skin. These glands make an oily substance called sebum. The pores connect to the glands by a canal called a follicle. Inside the follicles, oil carries dead skin cells to the surface of the skin. A thin hair also grows through the follicle and out to the skin. Sometimes, the hair, sebum, and skin cells clump together into a plug. The bacteria in the plug cause swelling. Then when the plug starts to break down, a pimple grows.