Africa and the Atlantic Slave Trade. Before the 16th century, Europeans were not deeply involved in slave trading on the West African coast. However, there was some movement of African labour to Madeira and the Canary Islands by the early Portuguese explorers from 1470 onwards.
urticaria is not contagious you cannot pass it on to another person acute urticaria or acute hives when symptoms last less than 6 weeks it is called acute urticaria this is by far the most common type 25 % of people with acute urticaria also have angioedema swelling in the deeper layers of skin
The rash or the hives produced in urticaria are very similar to the appearance of the rash in dermographism which is a raised bump that is itchy and pale red in color. Dermographism is not a serious and life-threatening disease.It is not a contagious skin disease although it is a life-long disease.The disease however has a good prognosis, especially the simple dermographism which is asymptomatic.he rash or the hives produced in urticaria are very similar to the appearance of the rash in dermographism which is a raised bump that is itchy and pale red in color. Dermographism is not a serious and life-threatening disease.