What Causes Rashes On The Lower Legs?

Hi there, I am 34 year old female, who has developed a bumpy itchy rash from the knees down on both legs. I went to the chemist and he has ruled out scabies, told me it was more likely to be contact allergy. Something my legs have come into contact with. The only thing I can think of is a moisturiser I've never used before. I used it after shaving my legs for about 3-4 days. Within 2-3 or days days the rash appeared. I am taking Piriton and putting Hydrocortisone on it. How long will the rash last for and what do you think triggered the reaction?

Thanks