Itchy spots (hives) or sometimes swelling (angioedema) can be a manifestation of allergies in the skin. Sometimes the itching is intolerable.
A proper diagnosis is important, but often hives can occur chronically without any apparent reason. We call this “idiopathic”. In such situations, symptomatic relief is important. Antihistamines are often helpful, but your doctor will review other options with you. The newer non-sedating antihistamines may be just as useful as older preparations. The older ones cause sedation, but don’t work any faster and aren’t any stronger than the non-sedating preparations.