Cinnamon oil is an aromatic oil derived from the bark and leaves of cinnamon trees. While cinnamon oil owes its medicinal properties to its alcohol and aldehyde content, some people may have negative reactions to these compounds. As these chemicals are present in high concentrations in cinnamon oil, allergic and toxic reactions are relatively common.
Aldehydes and Alcohols
Cinnamon oil contains a number of compounds that produce allergic, irritant or toxic reactions in some people. One of the main components of cinnamon oil is cinnamaldehyde, an aldehyde compound with potential fungicidal properties. While this lends cinnamon its medical uses in the treatment of yeast and respiratory tract infections, cinnamaldehyde is also its most allergenic compound. Among the alcohols in cinnamon oil is eugenol, another highly allergenic compound that contributes to its use as a mosquito repellent.
Most allergic or irritant reactions to cinnamon oil arise from its topical use. Whether applied medicinally or for its fragrant properties, cinnamon oil can cause a skin reaction known as contact dermatitis. This type of reaction leads to the development of redness, an itchy rash, swelling and hives on your skin. In irritant contact dermatitis, this allergy-like reaction typically occurs only at the point of contact. As allergic contact dermatitis activates your immune system, these symptoms tend to be more severe and widespread if due to a true allergy.
Due to its potent and agreeable flavor, the use of small amounts of cinnamon oil is common in toothpaste, candy and chewing gum. While not as common as contact reactions, some people have oral irritant and allergic reactions to cinnamon oil. Irritant oral reactions tend to be similar to other contact reactions, with common symptoms including itching, swelling and burning in and around the mouth. Allergic reactions may lead to sores, a burning sensation and excessive swelling of the lips, gums, tongue, cheeks and throat.
According to the experts at Phadia Laboratories, skin tests are not always accurate in detecting cinnamon food allergies. As a result, it is possible that you have no reaction unless you accidentally eat or breathe in cinnamon oil allergens. Although rare, Phadia states that an immediate allergic reaction to cinnamon oil is possible. Known as type I or type II hypersensitivity, an immediate reaction to cinnamon can cause skin, stomach and breathing problems. In severe cases, such reactions can progress to the life-threatening, full body allergic reaction known as anaphylaxis. Whether or not you have a known allergy, you should seek immediate medical attention if you experience a reaction after ingesting cinnamon oil.