Physical allergy

[Little_Girl]

A physical allergy is an allergic reaction triggered by a physical stimulus.
(See also Overview of Allergic Reactions.)
A physical allergy differs from other allergic reactions because the trigger is a physical stimulus. Physical stimuli include the following:

Cold
Sunlight
Heat or other stimuli that cause sweating (such as emotional stress or exercise)
Vibration
Minor injuries (such as those due to scratching)
Physical pressure

For some people, symptoms occur only in response to a physical stimulus. For some people who have other allergies, a physical stimulus makes symptoms worse.