There are widespread concerns about the risk of salmonella-based food poisoning stemming from eating contaminated eggs. The contamination is most prevalent on the surface of the shell, but there have been cases where the egg itself is infected, generally the yolk, but occasionally the white. The incidence of this poisoning is rare, but because the bacteria are killed when held at a temperature of 140°F (60°C) for 5 minutes or instantly at 160°F (71°C) people are taking pains to avoid raw or partially cooked eggs. Indeed, we are told that restaurants in New Jersey are prohibited by law from selling fried eggs sunny-side up, because they are considered undercooked.
Coddled eggs, whether cooked in the shell for three to seven minutes or in a ramekin in a water bath would certainly set off alarms at the Dept. of Public Health, because they have not reached the specified temperature. While government authorities caution everyone against eating raw eggs, they are especially adamant regarding small children, pregnant women, the elderly, and those with health problems.
In any event, you would not use coddled eggs for royal icing, a mixture of egg white and confectioner’s sugar, and sometimes a little lemon juice. You would not get the right texture. If you are concerned about eating raw egg, purchase powdered egg whites or meringue powder, both of which have been pasteurized, and reconstitute them according to the directions on the package.