The swellings or wheals produced after itching can be pale (of skin color) or red. Urticaria is usually triggered by allergens, such as
drugs, foods,
insect bites, inhaled substances, in response to sunlight, cold, heat, stress, exercise, or a viral infection. Other common allergens are pollen, mold, dust, pet dander, or cosmetics. Since you experienced an itch, just go over these possibilities in your mind. Something may strike you.