How can you differentiate an asthma from allergic rhinitis?

I have both. Asthma, it usually comes with cough and difficulty in breathing while allergic rhinitis could have several symptoms like itchiness in the eyes and nose, continuous sneezing, and it normally recurs at night time until early in the morning. Although these 2 are likely connected to each other. They just have different manifestations. Asthma is a form of an allergy also. You may check this out for further comparison between the two: http://www.worldallergy.org/public/allergic_diseases_center/caras/