A school in the US state of Rhode Island has sent a dramatic memo to parents warning of the health consequences of the "widespread phenomenon" of students snorting or smoking Smarties.

In a memo to parents, the school said students were "smoking" the candies by crushing them into a fine powder, pouring the contents into their mouths and blowing the "smoke" out of their mouths or noses.

"To snort Smarties, students use a straw or a rolled up piece of paper to snort the fine, crushed candy powder up into their nasal cavities,'' the memo said. Smarties in the US are different to the chocolate-centred Smarties found in Australia, as they are more like a fizzer type of lolly.

The school warned students who snorted or smoked Smarties ran the risk of cuts in their nasal cavity, infection, scarring, lung problems and allergic reactions. The school even claimed the habit could "lead to maggots feeding on the sugary dust wedged inside the nose'" and be a "precursor to future cigarette smoking and drug use".