اینافلیکسس (شدید الرجک ردعمل)

Overview

Anaphylaxis is the most severe form of allergic reaction, developing within minutes of exposure to a trigger and capable of causing collapse and death. It is a true emergency.

Causes

Common triggers include insect stings and bites, vaccines, certain medications, and some foods. The reaction occurs when the immune system overreacts to a substance it has become sensitized to.

Signs

Signs come on suddenly and may include facial swelling, hives, intense itching, drooling, sudden vomiting and diarrhea, difficulty breathing, pale gums, weakness, and collapse. In dogs, vomiting and collapse are prominent.

Diagnosis

Diagnosis is based on the sudden onset of severe signs following a likely trigger. There is rarely time for testing; treatment is started on clinical suspicion. In dogs, ultrasound may reveal a swollen gallbladder wall, a clue that supports the diagnosis.

Treatment & Management

Emergency treatment includes epinephrine, intravenous fluids to support blood pressure, oxygen, antihistamines, and corticosteroids, with close monitoring for delayed or recurrent reactions.

Prevention

Avoiding known triggers, monitoring animals closely after vaccines or new medications, and seeking immediate care at the first signs help prevent severe outcomes.

Animals that have had a severe reaction once are at risk of worse reactions in future and should be seen immediately at any recurrence. Because signs can return after initial improvement, a period of monitoring is advised.