Anaphylaxis is a potentially life-threatening systemic allergic reaction involving several organ systems. Recognition of the reaction leading to prompt treatment is essential for a good outcome. The lifesaving treatment is intramuscular injection of adrenaline (0.3-0.5 mg for adults and children > 40 kg, 0.3 mg for children 20-40 kg and 0.15 mg for infants < 20 kg). The patient must be placed on the back with elevated lower extremities to improve cerebral and cardiac circulation. High dose oxygen and crystalloid fluid load are needed to improve oxygenation and cardiac output.