Anaphylaxis effects and treatment side effects

During anaphylaxis, immune chemicals can widen blood vessels and cause tissue swelling. This may lead to hives, flushing, lip or tongue swelling, wheezing, vomiting, dizziness, faintness, or collapse. A person can have anaphylaxis without a visible rash.

Adrenaline, also called epinephrine, reverses dangerous airway swelling and supports blood pressure. After an injection, temporary trembling, palpitations, headache, pallor, or nervousness can occur. These expected sensations should not delay an indicated dose or emergency assessment.

Use the prescribed adrenaline auto-injector promptly in the outer thigh and call emergency services. Follow the device instructions and the person's action plan. Keep the person lying flat with legs raised if tolerated; if breathing is difficult, allow a supported sitting position. Do not let them stand or walk suddenly.

If symptoms continue or return and the action plan advises another available injector, give it as directed while waiting for help. Antihistamines may ease itching or hives, but they do not replace adrenaline for breathing difficulty, throat swelling, or circulatory symptoms.

Treat throat tightness, noisy or difficult breathing, wheezing, a hoarse voice, sudden persistent cough, blue or pale lips, confusion, faintness, or collapse as an emergency. Rapid symptoms affecting more than one body system after a possible allergen also require urgent action.

Emergency observation is needed even after improvement because symptoms can recur. Tell responders what triggered the reaction if known, when symptoms began, how many adrenaline doses were used, and what changed afterward.

Ask whether your symptoms fit anaphylaxis, which triggers need assessment, how to demonstrate your injector technique, and where to keep spare devices. Discuss whether allergy testing is suitable and request a written plan that family, school, or workplace contacts can follow.