Have you ever had an itch that just won't go away? One that screams out to be scratched, night and day, and gets worse the more you touch it? One that makes you dig your nails into your flesh until it bleeds, but still demands you scratch it?
If you haven't, count yourself lucky. Itchy rashes, whether caused by allergies, eczema, infections, dermatitis or parasites, are one of the most common, poorly understood and difficult to treat conditions people suffer.
But recently, researchers have come closer to finding out what causes the itch. Cytokines are proteins involved in making cells do the things they do - including dividing, growing and surviving. These proteins are particularly important for setting off immune system reactions, and are factors in a wide range of diseases.
So far, more than 60 of these interesting proteins have been discovered, and recently a new one, called interleukin 31, has been found that's thought to be a key player in causing the itchy rashes in allergies, dermatitis, psoriasis and eczema. If the protein is crucial in causing the itch, it should be possible to find ways to stop it from driving sufferers crazy.
This particular cytokine is produced by T-cells - the immune cells needed to attack viruses and other invaders trying to get through our skin. So, finding a way to tell these cells not to produce it at the wrong time is another possibility.
But before you can benefit from these or any other skin treatments, you need to know what kind of rash you have. Treatments vary greatly and what's good for one problem may be a disaster for another. Getting your itch diagnosed correctly is the first and most important step.