An allergy usually refers to a reaction by our immune system in response to certain allergens.The parts of the body that are prone to react to allergies
include the eyes, nose, lungs, skin, and stomach. If you do not have other signs or symptoms present, his rules out allergic causes. Your condition could be due to skin disorders, fungal infection, stress or head louse.
This could be due to contact dermatitis if there is a rash present with the itch.