Small bottle of essential mint oil
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Peppermint oil is a highly revered herbal remedy used for the treatment of respiratory problems, indigestion, headaches, nausea, irritable bowel syndrome, and urinary tract infections. It also contains a significant amount of nutrients including vitamin A and C, iron, magnesium, potassium, and calcium. Although peppermint oil is highly beneficial and nontoxic, some individuals may experience an allergic reaction and heartburn. If you experience adverse effects while taking this herb, stop using it and speak to a physician.

Peppermint Oil Allergic Reaction

Peppermint oil may be applied to the skin or taken by mouth in a capsule. An allergic reaction to peppermint oil is believed to be caused by alpha-pinene, limonene, and phellandrene. These naturally occurring substances are recognized as foreign and dangerous by the immune system, and trigger hypersensitivity. The immune system activates and recruits immune cells such as basophils and mast cells, and causes the release of histamine into the bloodstream and onto the skin surface. Histamine is an important immune mediator that causes inflammation, and results in a wide range of allergic symptoms -- from nausea, to vomiting and heartburn.

Allergic Skin Symptoms

Peppermint oil should be used cautiously and diluted with another oil as it can cause an allergic skin reaction. When peppermint oil is applied directly onto the skin, it can cause a hypersensitivity reaction in the skin, and the release of histamine by cells in the skin. Histamine dilates and increases the permeability of the blood capillaries on the upper layer of the skin, and allows fluids to leak into the skin. Redness, inflammation, and swelling of the area of skin exposed to peppermint is common. The release of histamine into the skin can result in hives. These hives are characterized as itchy, swollen lesions with a pale center. These hives typically occur within 24 hours of exposure, and may involve swelling of deeper layers of the skin. Allergic contact dermatitis is another type of skin reaction caused by peppermint oil. Allergic contact dermatitis is characterized by itching, redness and inflammation of the exposed area. Lesions or blisters that leak fluids, and eventually crust over, leaving the skin raw, thick, and scaly are also possible.

Allergic Respiratory Symptoms

Ingestion of peppermint oil can trigger an allergic reaction, followed by activation and infiltration of immune cells into the upper respiratory tract. Asthmatic symptoms such as wheezing, airway narrowing and shortness of breath is observed when peppermint oil is used on the chest, or near the nose. Peppermint oil can also irritate the nasal cavity, causing sinuses to swell. Nasal congestion, sneezing, sinus pressure, postnasal drip, facial pain and a runny nose is the result of this nasal irritation. Ingestion of peppermint oil can result in closing of the throat, narrowing of the airways, increased airflow resistance, and impaired breathing. The release of histamine by mast cells and basophils causes swelling of the upper respiratory tract, and impaired gas exchange in the lungs. As a result, wheezing, shortness of breath, coughing, and trouble breathing is also observed. If you experience any of these symptoms, seek immediate medical attention.

Other Allergic Symptoms

Ingestion of peppermint oil can result in an allergic reaction manifested in the digestive system. The release of histamine into the bloodstream causes irritation and inflammation of the stomach lining. As a result of this irritation, stomach cramping, diarrhea, nausea, and vomiting are commonly observed allergic reactions. Large doses of peppermint oil can lead to severe allergic reactions such as dizziness, slow heart rate, headache, anal burning, muscle tremors, muscle weakness, seizures and brain damage. Anaphylaxis may be observed in severe cases. Immediate medical attention is required if you experience dizziness, swelling of your tongue, lips and face, decreased heart rate or loss of consciousness.