Drugs that work by suppressing the immune system to keep it from attacking the body, such as Humira, Cimzia, Enbrel, and Remicade were found to cause high risk of fungal infection. Therefore, the Food and Drug Administration has asked the manufacturers to order stronger warnings for these prescription drugs that treat rheumatoid arthritis, Crohn's disease and other conditions. But apart from treating these conditions they also lower the body’s defenses to infections.

This warning was released after dozens of patients contracted severe fungal infections and died. Agency officials made reference to 240 reported infections caused by the fungus Histoplasma capsulatum in patients who took Enbrel, Humira or Remicade.

The FDA reported that 21 patients died because of the late finding of the infection. Among healthy people who live in areas where the fungi are endemic, over half will have had these infections by age 20, but in healthy individuals, it's either asymptomatic and they don’t even know they had it, or it's mild enough that it never makes it to their doctors' attention.

Dr. Jeffrey Siegel, who heads the agency's office for arthritis drugs, said the FDA discovered that about 20% of patients taking one of the drugs had died from histoplasmosis, which attacks the lungs and then spreads. The infection resembles a common flu, with fever and cough.

The FDA said the companies must submit new warning language which is to be approved within 30 days or give a reason why they protest the changes.