An allergic reaction is when your immune system reacts to normally harmless substances and the allergy commonly presents as red itchy rash e.g. urticaria, dermatitis. Very rarely, allergic skin rash can be serious and life threatening and requires immediate medical attention. Common allergens include medications, food, hair-dye, nickel, perfume and cosmetics.
Food allergy is a common clinical concern that Dr Wong encounters regularly and common allergens include cow’s milk, egg, peanut, shellfish, wheat and birdnest. However, true food allergy tends to be over-estimated due to over-reporting and subjective bias by patients. A careful and detailed clinical evaluation will help you to determine if your problem is truly related to food.
After a detailed medical history and a thorough clinical evaluation, Dr Wong will organise allergy testing e.g. skin prick test, skin patch test and allegy blood test to help you to confirm your allergy.
The skin prick test is a common method of confirming whether you are sensitive to the allergens suspected. A small needle is used to gently prick the skin through a drop of fluid containing a known allergen. Multiple pricks may be necessary and it is usually done on the forearm or on the back of young children.
The test is minimally painful and results are available 15 minutes later. The skin prick test is often done together with the IgE blood test for a more accurate diagnosis
Skin Patch Test
Patch testing is a way of identifying whether a substance that comes in contact with your skin is causing inflammation of the skin (dermatitis). Common triggers include fragrances (for example, in soaps), nickel (in jewellery, belt buckles and coins) and chrome (in leathers and bricklayers’ cement).
The test involves the application of various test substances to the skin under adhesive tape for 48 to 72 hours. The skin is examined later for any inflammation which will tell Dr Wong which test substance you are allergic to.
The main treatment of allergy is to avoid the allergens once they are identified. Dr Wong will also treat the skin rash with appropriate medications to control the reaction and symptoms. Commonly used medications include anti-histamine, anti-inflammatory agents, and immuno-suppressive medications when necessary