The FDA is warning doctors to prescribe two popular eczema treatments with caution after concerns over a possible cancer risk associated with their use.

The two creams, Elidel and Protopic, will also soon carry the FDA’s strongest“black box” warning on their packaging to alert doctors and patients to these potential risks. The warning advises doctors to prescribe short-term use of Elidel and Protopic only after other available eczema treatments have failed in adults and children over the age of 2.

At a meeting last month, the FDA’s Pediatric Advisory Committee reviewed research in animals that linked Elidel and Protopic to an increased riskof skin cancer and non-Hodgkin’s lymphoma. In those studies, the risk of cancer increased as the dose of the drugs increased.

Research presented at the meeting also linked Elidel and Protopic to about 25 cases of cancer in adults and children who used the drugs.