History: Depending on the system involved, the individual may complain of itching, rash, swelling, sneezing, runny nose, tearing, earache, sore throat, cough, breathing difficulties, and gastrointestinal symptoms like diarrhea. Individuals may describe certain conditions that trigger their symptoms. For example, they may report that the symptoms arise every time they are around animals or worsen in the spring and disappear during winter.
Common symptoms associated with reactions to latex are skin rashes, eye irritation (conjunctivitis), runny nose (rhinitis), narrowing of airways (bronchospasm), and even anaphylaxis. Physical exam: The lungs, heart, and all other body areas affected by the allergic symptoms are examined. In mild cases of allergic rhinitis, the exam may reveal swelling and inflammation of the nasal passages and nasal discharge. Swelling, redness, and tearing of the eyes are common in allergic conjunctivitis. Additional findings of redness and swelling in the ear canal and throat are not uncommon.
Large, irregular, red bumps on the skin (hives) may be present with food allergies, drug allergies, or allergic reaction to insect stings. Gastrointestinal symptoms are most common with food, food preservatives, and food additive allergies.
Wheezing or absent lung sounds and a rapid respiratory rate may be present in asthma or anaphylaxis. Cool, moist, and pale skin in conjunction with a rapid pulse and low blood pressure may be signs of shock due to anaphylaxis. Tests: In addition to a physical exam, one or more diagnostic tests may be done. These tests help determine what triggers the allergy and evaluate the severity of the allergic reactions.
A spirometer measures the amount of air entering and leaving the lungs (spirometry). It is useful in identifying lung disorders such as asthma that may cause narrowing of the airways.
In a scratch test, small amounts of the suspected allergen (e.g., dust, dander, or food) are placed on the skin surface. Development of a small, raised bump on the skin indicates an allergic response to that particular substance. In intradermal tests, small quantities of the suspected allergen are injected under the skin. A reaction of redness or swelling at the injection site indicates an allergic response. The radioallergosorbent test (RAST test) is a blood test used in individuals with disorders that may interfere with skin testing.
The patch test involves applying adhesive patches with allergens to the skin. Localized redness and swelling at the application site indicate positive reaction. In a challenge test, the suspected foods or medications are eliminated for a period of time and then, under medical observation, small amounts are reintroduced to see if they trigger an allergic reaction. |