British scientists say they have discovered how cats trigger allergies in people, raising hopes for a possible cure to the feline-caused affliction.

Researchers at the University of Cambridge say they have found a protein in cat dander — or dead skin cells — that interacts with a chemical in the human body to cause allergy symptoms, which can range from itching and sneezing to asthma attacks.

When the dander is released in the presence of a common environmental bacterial toxin called lipopolysaccharides, or LPS, it activates a immune receptor called TLR 4, triggering allergic reactions.

"How cat dander causes such a severe allergic reaction in some people has long been a mystery," said Clare Bryant, the lead author of the study. "Not only did we find out that LPS exacerbates the immune response’s reaction to cat dander, we identified the part of [the] immune system that recognizes it."

The researchers then used a drug that inhibits TLR 4 and blocked the allergic response.

"As drugs have already been developed to inhibit the receptor TLR4, we are hopeful that our research will lead to new and improved treatments for cat and possibly dog allergy sufferers," Bryant added.

The only treatment currently available to allergy sufferers are antihistamines, which can also generate a rash of side effects, including drowsiness and nausea.

The discovery could be used to create a drug, delivered in pill form or through an inhaler, that researchers say could effectively block the allergic reaction.

Cat allergy study in Hamilton

A research study called CATALYST, studying treatment designed to relieve cat allergy symptoms is currently underway at McMaster University in Hamilton.

The study aims to determine if medication is effective at reducing cat allergy symptoms such as sneezing, and itchy, watery eyes. The study is a Phase 3 clinical trial, meaning that the medication used in previous clinical trials has been found to be safe and can be tolerated by people suffering with cat allergy.

More than 1,100 cat allergy sufferers between the ages of 12 and 65 are being recruited from seven different countries to participate in this study. The study is being funded by pharmaceutical company Circassia LTD.