You've probably heard of indoor allergens such as mold or dust mites, but what about the Asian ladybug? In recent years researchers have pegged the beetles as a source of allergic symptoms including hay fever, coughing, wheezing and watery eyes.
Asian ladybugs, formally known as multicolored Asian lady beetles, were introduced to the U.S. as early as 1916 to control the aphid population, but the beetles don't like the cold, so they regularly swarm into houses when the temperature drops.
"These things come in in the winter, and you have real trouble," said Dr. Thomas Platts-Mills, professor of medicine, allergy and clinical immunology at the University of Virginia. "And they actually bite, occasionally."
Indoor clusters can number in the thousands. Beginning in the late 1980s, homeowners began to report large indoor swarms in Louisiana.
The beetles are now well-established along the East Coast, in parts of the Midwest, and the Southeast. They look similar to North American ladybugs but vary in color from yellow to brown and scarlet, with polka-dots optional.
Allergy experts such as Platts-Mills refer to the Asian ladybug as a "new seasonal indoor allergen."
The best advice for preventing an Asian ladybug infestation is to seal the cracks and crevices in your home that could let them in, said Donald Lewis, professor of entomology at Iowa State University.
Once they're inside, Lewis suggests: "You can spray them to kill them, but you might as well use your vacuum cleaner to suck them up."
Medications are designed to make us better, but on occasion, a drug sparks an allergic reaction that can kill.
In the case of cetuximab, also known as Erbitux, an intravenous drug given to people with colon cancer as well as head and neck cancer, an unusually high rate of allergic reactions in patients from certain parts of the U.S. puzzled doctors.
When researchers studied cetuximab in clinical trials, they reported serious allergic reactions in 3 percent of patients taking the medicine. But when the drug became widely available, a significantly higher number of patients in Tennessee and North Carolina -- more than 20 percent -- had severe allergic reactions when they began using the same drug.
Researchers studying the geographical differences eventually discovered that most of the people who had an allergic reaction to cetuximab also had a previously existing antibody in their blood that targeted a specific sugar on the cetuximab molecule, causing the immune response.
"The antibodies were there before they were treated, and they predicted what happened to them," said Platts-Mills, who co-authored the research paper.
So where did the antibody come from, and why do more people in Tennessee and North Carolina have it?
Platts-Mills theorizes that patients developed the antibody before they took the drug when their bodies staged "a very aggressive immune response" to a seed tick bite, but he has yet to determine exactly why the person makes this particular antibody after the bite.
"In the area where this thing is going on, tick bites are much more common than people realize," said Platts-Mills.
The ongoing research is being closely followed by other allergists intrigued by the findings.