Grammar 101 with Michael Kwan

The words “allergic” and “allergenic” are both related to allergies, but they have different meanings and cannot be used interchangeably. This is similar to what we find with word pairs like venomous and poisonous. A snake might be venomous (active administration of poison), while certain plants might be poisonous (passive administration of poison). So, what’s the difference between something that is allergic and something that is allergenic?

Going back a step, we must first define a couple of related terms. An allergy is the (often uncomfortable) immune response that the body may have to a particular substance. It is common for someone to have a pollen allergy, for example, causing him or her to sneeze uncontrollably. In this example, the pollen is an allergen. It is the substance that is causing the negative reaction in the body.

The word allergic is an adjective, used to describe something that is caused by or related to the allergy. Most commonly, you may hear the term “allergic reaction.” These are the symptoms exhibited by the person who is experiencing the reaction. By extension, the person experiencing the allergic reaction is said to be allergic to the allergen causing the reaction.

  • Herman is allergic to peanuts.
  • Peanuts cause an allergic reaction in Herman.

The word allergenic is also an adjective, but it is used to describe the property of acting like an allergen. It refers to the characteristic or attribute of being an allergen. The word “allergenic” has the same meaning as “allergy-causing.” More commonly, you’ll hear about products that are “hypoallergenic,” meaning that they are less likely to elicit an allergic response.

  • The baby developed rashes with those other diapers, so we bought these hypoallergenic diapers instead.
  • The Obama family chose a hypoallergenic breed of dog.
  • The leaves on this fern have allergenic properties.

Something is allergenic is on the “sending” side of this transaction (the “cause”), while something that is allergic is on the “receiving” side (the “effect”). The peanuts are allergenic, but Herman is allergic. The plant leaves are allergenic, but the reaction you get from touching them is allergic.

You can think about this relationship the same way that you can understand the difference between a benefactor and a beneficiary, except allergic reactions are rarely ever a pleasant experience. I’d know. My eyes have been quite itchy lately (allergic reaction), but I haven’t been able to pinpoint what’s causing that (allergenic substance). It’s driving me crazy.