Teenagers in the Midwest land in hospitals after developing severe breathing problems from steam, and no one knows why.
A total of 22 people in Minnesota, Wisconsin and Illinois have been hospitalized after vaping, according to NBC News . It includes the eight cases reported in Wisconsin at the end of July, according to a previous Live Science report .
Patients reported cough, shortness of breath and fatigue, and sometimes vomiting and diarrhea, according to a statement from the Illinois Department of Public Health. Teenage symptoms gradually worsened before they arrived at the hospital.
A patient in Wisconsin must be placed in a medically induced coma after his lungs begin to fill with fluid. He has since been discharged and is currently recovering according to NBC News.
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It is unclear what these cases have in common, other than vaping. But state health departments, the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) are working to identify e-cigarettes used by teens and which chemicals the patients may have inhaled, according to the statement.
The FDA does not require e-cigarette manufacturers to list the ingredients in their products. In addition, some of the teens may have bought vaping products on the street rather than in stores, according to NBC News.
"The short- and long-term effects of vaping are still being researched, but these recent hospitalizations have shown that there is potential for immediate health consequences," Dr. Ngozi Ezike, head of the Illinois Department of Public Health, said in the statement.
Originally published on Live Science .