A routine blood count which include eosinophil count and an Ig E levels, can help to differentiate among various causes for you skin condition. Most common allergens are dust, pollen and animal dander and certain food (tomatoes, egg, brinjals, some sea food). If you know what causes your allergy, best option is to totally avoid it.
Next Steps
If you do not know what causes the alleric reaction, you can do skin allergy tests.
Health Tips
desensitization therapies are also available.