If the rash has been bothering you for over a week and still shows no signs of going away, you should visit a doctor as it could be an unusually severe allergic reaction or some entirely different problem such as an infection. Normally, even an allergic rash or a reaction to some irritant should last for just two or three days, but in some cases they last longer and you may need to take some medication to treat the reaction, such as antihistamines to end the reaction.
There is no real cure for a rash, your body will slowly return to normal on its own without any treatment, unless, as mentioned before, the reaction is unusually severe, in which case appropriate medication may need to be prescribed by a doctor after investigating a symptoms. Apart from this, treatment only involves easing the itching and burning. First of all, you should avoid scratching the rash at all costs, as this will worsen it and also invite infection. If you have not already tried a cold compress, you should do so - an ice pack is an excellent treatment, but if you find it too cold and uncomfortable, you can also dip a soft cloth in cold water. You can also apply aloe gel to the affected skin, if possibly using gel from a freshly broken leaf of the plant.
answered by M W