Causes of urticaria
Urticaria is always thought to be allergic but in reality only 20% of cases is caused due to allergy to certain food or medicines which a person has eaten or certain chemicals or plants/animals a person has come in contact with. Patient is able to identify the allergen in most of the cases.
In 80 % of cases allergic cause cannot be found. Blood and skin test for allergy is negative. This type of urticaria may be termed as immunological.
It can be termed as individual hypersensitivity to certain allergens such as :
- Urticaria caused after exposure to heat, after exercise or pressure.
- After use of painkillers or anti hypertensive medicines or use of statins for cholesterol or non steroidal anti inflammatory medicines.
- Urticaria is caused or aggravated after taking alcohol or drugs.
- Emotional stress is one of the major aggravating factors in chronic and recurrent urticaria.
- Other systemic illness where immunity is compromised can cause urticaria.