**Question:** Immediately after eating, a man develops swelling of face and lips, respiratory distress, intense pruritis, hypotension and feeling of impending doom. Which of the following is the most likely diagnosis?

A. Anaphylaxis
B. Angioedema
C. Angina
D. Food poisoning

**Core Concept:** Anaphylaxis and angioedema are two severe allergic reactions with overlapping symptoms. Anaphylaxis is a systemic allergic reaction that can affect multiple organ systems, while angioedema is a localized swelling of the skin, mucous membranes, and subcutaneous tissues.

**Why the Correct Answer is Right:** The correct answer is A. Anaphylaxis because the patient experiences pruritis, hypotension, and swelling of face and lips, which are characteristic of this severe allergic reaction. Anaphylaxis is characterized by rapid onset of symptoms and can lead to respiratory distress and hypotension.

**Why Each Wrong Option is Incorrect:**

B. Angioedema: This option is incorrect because angioedema is a localized swelling of the skin, mucous membranes, and subcutaneous tissues. While the patient may have facial edema, the other symptoms are not present.

C. Angina: Angina is a condition characterized by chest pain due to reduced blood flow to the heart muscle. The presented symptoms do not align with angina, which is caused by ischaemia, not the severe allergic reaction.

D. Food poisoning: Food poisoning is an acute gastrointestinal infection caused by contaminated food. The patient's symptoms, including pruritis, hypotension, and respiratory distress, are not consistent with food poisoning.

**Clinical Pearl:** Prompt recognition and management of anaphylaxis is crucial as it can rapidly progress to severe hypotension and respiratory failure. In severe cases, it can lead to cardiac arrest and death. If anaphylaxis is suspected, initiate immediate treatment (e.g., intramuscular adrenaline [epinephrine], oxygen therapy, and close monitoring of vital signs, while referring the patient to a tertiary care center for further management.**

**Correct Answer Explanation:** Anaphylaxis is a severe, potentially life-threatening systemic allergic reaction that affects multiple organ systems. It is characterized by rapid onset, causing pruritis, hypotension, and respiratory distress. The swelling of the face and lips in this case is due to angiotensin-converting enzyme (ACE) inhibitors, which are vasodilators, can cause facial edema as a side effect. However, the patient's severe pruritis, hypotension, and respiratory distress point towards a more severe allergic reaction (anaphylaxis).