Q: When children are sick, why does their nasal discharge turn green?
A: The presence of immune cells that fight infections, as well as disease-causing germs themselves, alter mucus color as an illness like a cold progresses in both children or adults. Clear mucus may be a response to an infection, but green mucus is not necessarily a green light for taking an antibiotic.
“When germs that cause colds first infect the nose and sinuses, the nose makes clear mucus,” says a fact sheet published by the Centers for Disease Control and Prevention. “This helps wash the germs from the nose and sinuses.”
After two or three days, the body’s immune cells fight back, changing the mucus to white or yellow. “As the bacteria that live in the nose grow back, they may also be found in the mucus, which changes the mucus to a greenish color,” the CDC says.
The green discharge is normal, and contrary to what many people believe, it does not mean that the sufferer needs an antibiotic. An antibiotic is ineffective against a virus, and there is also a risk of producing antibiotic resistance in other disease-causing organisms.
The type of infection cannot be determined by looking at mucus color. Instead, a sputum analysis should be done.
Other factors to be considered in deciding on treatment include the quantity, viscosity and odor of the mucus. Sometimes a microbial culture is necessary to identify the infecting organism.