The severity of symptoms can vary between people. Mild symptoms may include: Abdominal pain. Diarrhea. Coughing. Hives. Itching (pruritus). Nausea or vomiting. Rash. Tingling or swelling of your lips, tongue or throat. Severe symptoms may include anaphylaxis. Without immediate treatment, anaphylaxis can be fatal. Other severe symptoms may include: Confusion. Difficulty breathing. Difficulty swallowing (dysphagia). Dizziness. Drop in blood pressure (hypotension). Loss of consciousness (syncope). Shortness of breath (dyspnea). Tightness in your chest or throat.