ASVAB Practice Test

According to the passage, which of the following statements is NOT true about allergies?

1. Immune system malfunctions cause allergies

2. Medical science does not fully understand why the body has an allergic reaction to certain substances

3. Histamine causes allergic symptoms such as headaches and rashes

4. Allergies are always due to harmful substances

The correct answer is: Allergies are always due to harmful substances

The correct choice indicates that allergies are not always due to harmful substances. In reality, allergies can be triggered by substances that are generally harmless to most people, such as pollen, certain foods, or pet dander. The immune system mistakenly identifies these benign substances as threats and overreacts, leading to allergic reactions. The other statements correctly reflect the nature of allergies. Immune system malfunctions indeed play a significant role in the development of allergies since they involve an inappropriate immune response. Furthermore, it is true that medical science has not fully elucidated why certain individuals develop allergies to specific substances, suggesting gaps in our understanding. Histamine is a key mediator in the allergic response, and its release can lead to various symptoms, including headaches and rashes.