The mesquite shrub or tree belongs to the genus Prosopis and thrives in dry climates. Several species occur in the arid regions of Southwestern United States and Northern Mexico, including P. juliflora, P. velutina, P, pubescens and P. glandulosa. Its presence causes allergic reactions in people with sensitivities.
Mesquite Pollen Allergens
Allergies result when a person’s immune system overreacts to a substance called an allergen. Mesquite pollen contains at least 13 proteins that provoke allergic reactions. These proteins are distinguishable from one another by their molecular weights. A glycoprotein with an atomic weight of 20 kilodaltons is especially prone to produce allergic reactions, according to “Clinical and Molecular Allergy.” A proton weighs 1 dalton, and a kilodalton equals 1,000 daltons, so a 20 kilodalton glycoprotein has as much weight as 20,000 protons.
Airborne Allergens
Wind blows mesquite pollen from male flowers to their female counterparts. The mesquite tree produces a great quantity of pollen, so that at least some of it reaches its intended destination. However, some of this pollen reaches people who are allergic to it, so that they suffer an allergic reaction without touching the tree. Wind carries the pollen a considerable distance from its source and may cause allergies in people who live more than 50 miles away from the nearest mesquite tree, according to the “Journal of Allergy and Clinical Immunology.”
Wood and Smoke
Mesquite wood contains some of the same allergens as mesquite pollen. When mesquite wood is burned, the allergens persist in the smoke. For this reason, sensitized people have suffered allergic reactions when exposed to the smoke of burning mesquite wood. Others have suffered after eating food barbecued with mesquite wood, according to the “Journal of Allergy and Clinical Immunology.”
Mucous Membrane Inflammations
Mesquite allergies often take the form of mucous membrane inflammation. Sometimes mesquite allergens cause rhinitis, meaning “inflammation of the nose.” They also cause conjunctivitis where the conjunctiva, a mucous membrane of the eye, becomes inflamed. Sometimes they cause rhinoconjunctivitis, a condition in which both the conjunctivae and the mucous membranes of the nose become inflamed. Mesquite allergens may even affect the breathing apparatus so that asthma results.
Allergic Contact Dermatitis
When a mesquite allergen comes into contact with the skin of a sensitized person, allergic contact dermatitis may result. Dermatitis is an inflammation of the skin. It manifests itself in rashes and blisters. Even those not allergic to mesquite allergens may experience skin irritation on contact, according to the Washington State Department of Labor and Industry.
References
- "Clinical and Molecular Allergy"; The Human Allergens of Mesquite...; S. Killian, et al; July 2004
- All Allergy: Honey Locust tree / Mesquite tree
- Northwestern University Department of Molecular Biosciences: Dalton
- Phadia: Mesquite
- "Journal of Allergy and Clinical Immunology"; Identification of...; D. More, et al; Nov. 2002
- "Sultan Qaboos University Medical Journal"; The Pattern of...; Salem H Al-Tamemi, et al; Nov. 2008
- "Journal of Allergy and Clinical Immunology"; Mesquite Pollen...; Harold Novey, et al; May 1977
- Washington State Department of Labor and Industries: Phytodermatitis...
