**Question:** Chostek's and Trousseau's Signs is seen in which poisoning?

A. Acid Poisoning (e.g., Acid Ingestion)
B. Alkalinity Poisoning (e.g., Alkaloid Ingestion)
C. Glucose Poisoning (either high or low)
D. Dehydration (resulting from severe diarrhea or vomiting)

**Correct Answer:** A. Acid Poisoning (e.g., Acid Ingestion)

**Core Concept:** Chostek's and Trousseau's Signs are clinical signs observed in patients poisoned by acidic substances. They are named after their discoverers, Chostek and Trousseau, who first described these signs in acid poisoning patients.

**Why the Correct Answer is Right:** Chostek's Sign is characterized by the appearance of a "flash of erythema" at the site of injection of local anesthetic agents (e.g., lidocaine) into the extremity. This sign indicates the presence of acidosis, which is commonly seen in acid poisoning. In acid poisoning, the decreased pH causes an increased permeability of capillaries, leading to extravasation of plasma proteins and the appearance of the red "flash." Chostek's Sign is a useful diagnostic tool for acid poisoning.

Trousseau's Sign is characterized by the development of a "flash of pallor" following a digital nerve stimulation. This sign is related to acidosis-induced vasodilation, which causes a temporary decrease in blood flow to the digit. Trousseau's Sign is also useful in diagnosing acid poisoning, particularly in cases where Chostek's Sign is not present or is equivocal.

**Why Each Wrong Option is Incorrect:**

B. Alkalinity Poisoning (e.g., Alkaloid Ingestion): Acidosis and alkalosis are the two extremes of pH balance, and neither sign is seen in alkalinity poisoning. Alkalinity poisoning typically causes alkalosis, which leads to peripheral vasoconstriction and decreased blood flow to the extremity, resulting in pallor and coldness (not the desired outcome).

C. Glucose Poisoning (either high or low): Both high and low glucose levels can lead to acidosis or alkalosis, respectively. Neither sign is specific to glucose poisoning and can be observed in other conditions causing acidosis or alkalosis.

D. Dehydration (resulting from severe diarrhea or vomiting): While dehydration can contribute to acidosis, neither Chostek's nor Trousseau's Sign is specific to dehydration. These signs are primarily related to acidosis caused by poisoning, not dehydration.

**Clinical Pearls:**

Chostek's and Trousseau's Signs are useful diagnostic tools for acid poisoning in patients presenting with signs of acidosis, such as altered mental status, respiratory distress, or shock. The presence of these signs indicates the need for