Allergies in the fall and winter seasons are considered for the following reasons: 1, sunlight ultraviolet radiation allergy, usually occurs in the skin more sensitive people, autumn and winter seasons, ultraviolet light is relatively weak, but for sensitive groups a little ultraviolet light can also cause allergies. 2, the weather is too dry in the fall and winter seasons, leading to a large amount of loss of moisture in the skin, and the surface of the skin appeared in the small breaks, caused by epidermal parasites of the epidermis of the staphylococcus epidermidis bacteria invasion, causing inflammation and allergic reactions. 3, for pollen, tree hair and other easily sensitized inhalation group allergies and lead to allergic reactions.