What causes the urge to scratch? [Video]

Having an itch that you just can’t scratch is one of the most frustrating experiences – but it might actually be beneficial in the long run, according to scientists from the University of Pennsylvania.

“That persistent itch, or pruritus, may actually be one of the skin’s first lines of defense against harmful invaders,” said a press release from the university citing neuroimmunologist Juan Inclan-Rico. He’s a postdoctoral researcher in the Herbert Lab at Penn’s School of Veterinary Medicine and part of a team that published a recent paper on the topic in the Nature Immunology journal.

According to the Cleveland Clinic, pruritus can have many causes. Some of the most common are allergens, dry skin, pregnancy and reactions to medication. Sometimes, the location of the itch may indicate its cause – for example, upper arm itching can be associated with brachioradial pruritus caused by nerve damage.

Inclan-Rico said itching is also one pf the ways the body detects threats …