Listeriosis is a disease caused by infection with the bacterium Listeria monocytogenes, and it is most often contracted after eating contaminated foods or liquids. Listeriosis most commonly affects newborns, the elderly, pregnant women, and those individuals with a poorly functioning immune system (immunocompromised).
I have been on Plaquenil and can tell you my diarrhea started within days of starting the med. My doctor warned me that diarrhea and weight loss were side effects. I said, Well, I am usually very constipated and could stand to lose 10 pounds so this could be a good thing.. haha.
Rheumatologist prescribed Plaquenil for inflamation due to autoimmune disorder. On third day, I developed an itchy bright red rash on neck. Stopped medication and started taking Benadryl for the itch. Two days later the rash spread to my chest, stomach, and back. Went to urgent care where I was told it was most likely a reaction to the Plaquenil. Received a cortisone shot and a prescription for Prednisolone (six day pack), and an antihistamine.