ANAPHYLACTIC SHOCK

Symptoms of anaphylactic shock

For further information: Anaphylaxis Symptoms

Anaphylactic shock is a particularly severe allergic reaction, which occurs only in certain circumstances. Knowing how to recognize the symptoms promptly is therefore essential to stop the triggering of a cascade of haemodynamic events that can lead to the patient's death.

The symptomatic picture associated with anaphylactic shock, complex and multifaceted, generally passes through a series of manifestations of increasing severity:

abrupt drop in blood pressure and tachycardia → prodrome of anaphylactic shock: intense pallor, generalized urticaria (itching that usually begins in the hands and feet), profuse sweating with cold skin, dizziness, generalized sense of severe malaise, anxiety, anguish, hoarseness, lowering of voice, dysphonia, angry cough;

→ upper respiratory tract angioedema → bronchospasm and severe breathing difficulties, tachypnea with shallow breathing (hypocapnia); enteric symptoms may appear (abdominal pain, nausea and vomiting) and a generalized skin reaction is appreciated (widespread redness and itching);

→ cyanosis (bluish discoloration of the skin) and a marked sensation of suffocation;

→ circulatory collapse, loss of consciousness and convulsions → coma and death that occurs following asphyxia, severe hypoxia or cardiac arrest linked to severe hypotension.

The appearance of the typical symptoms of anaphylactic shock follows the "exposure to the allergen for a time ranging from a few seconds to over an" hour (average interval less than 10 minutes), thus undergoing the influence of various factors, such as the structure and the route of introduction of the antigen (oral, inhalation, intravenous ...). In the forms with rapid onset, for example, anaphylactic shock appears abruptly, separated from the prodrome just listed.

Since only a timely and adequate therapy can gradually bring the vital parameters and the clinical picture back to normal, the prognosis is all the more serious the shorter the time that elapses between the exposure to the allergen and the appearance of the typical clinical picture. of anaphylactic shock. Furthermore, it is known that the severity of the allergic reaction is inversely proportional to the time of onset, even if in some cases a serious symptomatology can manifest itself after a few hours.

INCIDENCE OF ANAPHYLACTIC SHOCK: estimated at 30-50 cases per 100,000 inhabitants per year, with a mortality of 0.0006% (in the United States it is estimated that one death in 1600 is due to anaphylactic shock, while the population considered at risk is between 1 and 15 percent).