Anaphylactic shock

Anaphylactic shock is an extreme allergic reaction against an antigen to which a person has become hypersensitive. This medical event necessitates immediate emergency room care.

Left untreated anaphylactic shock can cause rapid unconsciousness and even death. 
According to the World Health Organization (WHO), allergy is the fourth leading chronic disease.

Anaphylactic shock has a prevalence of one to three cases per 10,000 people and it kills one to three million people per year. WHO estimates that 50% of the world's population will be affected by allergy by 2050.