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Scientists Solve Long-Standing Poison Ivy Mystery

Summer is a time for getting away from our computers and spending time in nature (supposedly). Sometimes, though, the natural world can be unfriendly. The great outdoors are full of dangers, some more serious than others. One of the less serious but nonetheless annoying perils found in nature is the infamous Toxicodendron radicans plant, or poison ivy as its colloquially known.

Just remember the saying: leaves of three, shoulda stayed home.

Just remember the saying: leaves of three, shoulda stayed home.

Despite plaguing humanity for ages with its maddeningly itchy rash, poison ivy’s exact mechanism from which it draws its name has been unknown – that is, until an international team of botanists and medical researchers conducted a study to determine what exactly causes the human reaction to the plant.

Like I said, shoulda stayed home.

Like I said, shoulda stayed home.

According to the research published in Nature Immunology, part of the mystery surrounding poison ivy has to do with a molecule produced by the skin called CD1a. While this molecule has long been suspected as one of the key factors in the human reaction to poison ivy, this theory has been difficult to test due to the fact that CD1a is not produced in laboratory mice which are commonly used (and approved) for skin testing. Thus, to test the interaction of CD1a and urushiol, the active toxin in poison ivy, a team of researchers genetically engineered mice which produce the protein and rubbed them down with poison ivy leaves to see what would happen.

You know what - I think I'll just never go outside again.

You know what – I think I’ll just never go outside again.

As was predicted, the mice broke out in terrible itchy rashes – all in the name of science, naturally. The mechanism was found to be a specific inflammatory response caused by the CD1a proteins on the mice’s skin. One of the lead authors of the newly published research, Dr. Jerome Le Nours, claims that this is the first research to connect CD1a with poison ivy inflammation and itch:

For over 35 years we have known CD1a is abundant in the skin. Its role in inflammatory skin disorders has been difficult to investigate and until now has been really unclear. Our work represents clear evidence that CD1a is instrumental in skin-related diseases. We are the first scientists to image the CD1a–urushiol connection.

Luckily for those of us who regularly deal with the itchy rash, Le Nours speculated that this research could lead to better prevention and treatments for poison ivy inflammation:

We now have a target to further investigate. Our basic discovery may make a big difference in the future treatment and prevention of inflammatory skin diseases.

According to the American Skin Association, poison ivy is one of the most common allergic reactions worldwide, affecting nearly 85% of people with mild to moderate inflammation, and affecting another 10-15% with severe reactions. Let’s hope those itchy genetically-engineered mice can lead scientists to a cure sometime soon.