The clinical presentation of allergological emergencies is heterogeneous. The most important conditions are anaphylaxis (which is frequent) and Stevens-Johnson syndrome or toxic epidermal necrolysis (which are rare). In the acute phase it is most important to recognize the exogenous elicitation of the condition as soon as possible, otherwise severe sequelae, even death of the patient, may occur. Management is based on immediate elimination of possible causative agents and symptomatic therapeutic measures. Furthermore, allergological diagnostics are necessary without delay to identify what has elicited the reaction. This information makes possible long-term treatment in order to avoid further hypersensitivity reactions.