Can Allergies cause Fatigue and Weakness?

Allergies are an exaggerated response of immune system that perceives something as a potential threat to the body. Thus, immune system promotes the production of histamine.
The uncontrolled release of histamines form allergy.

Why allergies cause fatigue?
 

Histamines consume too much energy to the body. They dilate blood vessels, accelerate the heart rate and also promote the release of adrenaline. Body becomes exhausted to solve a problem without value, and ultimately it create a much bigger problem. When this process worsens, occurs an increase in temperature and can cause fever, muscle spasms, shortness of breath and even cardiac arrest.

Theoretically histamines submit the body to big levels of stress. And stress, begins the second problem ... wich can be depression (for example).
Studies shows that there is a relation between allergies and depression. But many other problems can be developed.

Allergies are still little explored. Scientists want to understand why only some bodies are sensitive to certain external agents (antigens) and finally find a permanent cure for allergies.