While generally considered a safe, edible wild mushroom, the morel mushroom can cause an allergic reaction in some individuals. If you have never eaten a morel or suspect that you may have an allergy to morels, keep a close watch for symptoms of a reaction and take special precautions to avoid triggering any severe symptoms. Additionally, only consume mushrooms you can clearly identify; do not eat a mushroom unless you are sure it is edible.
As with any food allergy, the symptoms of morel mushroom allergy range from mild to severe. According to MayoClinic.com, many common symptoms affect the digestive system and include abdominal pain, diarrhea, nausea and vomiting. Other common symptoms include itching of the mouth, swelling of the lips, tongue or throat, hives, wheezing, nasal congestion and dizziness. Someone with a severe allergy may experience a rare, serious condition called anaphylaxis, in which the throat swells and makes breathing difficult. Anaphylaxis often triggers rapid pulse, a drop in blood pressure and severe lightheadedness. An allergic reaction may start almost immediately or may occur several hours after consumption.
As explained in "Morel Mushrooms: A Guide for Selection and Use," by Julie Cascio and Marci Johnson of the University of Alaska Fairbanks Cooperative Extension Service, consuming alcohol increases your risk of having a reaction to morel mushrooms. Most often, alcohol increases your risk of experiencing allergy symptoms directly associated with the digestive system. In rare cases, however, the mixture of alcohol and morels can cause faintness. Your odds of experiencing gastrointestinal upset also increase when you eat old morels. Strictly speaking, this does not occur due to a food allergy, but simply because the mushroom went bad in the same way a vegetable or fruit might spoil and rot.
Certain precautions help reduce your risk of experiencing an allergic reaction to morels. In the article "Morels: Pitted Delights," Robert Fogel recommends that, if eating morels for the first time, you should taste a small sample before eating a meal made with the mushrooms. Even if no symptoms occur, use a small amount of morels in your first meal before gradually increasing the amount you include. Ellen Horowitz of "Montana Outdoors" recommends throwing away any morel with an odor or any morel that came from an area sprayed with chemicals.
An over-the-counter antihistamine treats most mild reactions. If you experience only a mild reaction, you may not need to visit the doctor. From that point on, however, you must avoid eating morels. A minor reaction can lead to a major reaction later on. If you do plan on consuming morels after having an allergic reaction to them, make sure you have an antihistamine on hand. Your doctor may also recommend having an epinephrine auto-injector in case you have a severe reaction. If you end up having a severe allergic reaction after eating morels, seek emergency medical treatment.