Magnan’s symptom is seen in?
**Core Concept**
Magnan's symptom is related to a specific condition involving the nervous system, particularly concerning **tactile hallucinations**. This symptom is a type of hallucination where an individual feels something on their skin that is not actually there. The underlying principle involves the **neurological pathways** responsible for processing sensory information.
**Why the Correct Answer is Right**
The correct answer involves a condition where Magnan's symptom is commonly observed, which is **cocaine bug** or **formication**, a condition associated with **substance abuse**, particularly cocaine. This symptom arises due to the effects of the substance on the **central nervous system**, leading to **tactile hallucinations** where the individual feels like bugs are crawling under their skin.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not relate to the specific condition associated with Magnan's symptom.
**Option B:** Similarly, this option does not correspond with the condition characterized by Magnan's symptom.
**Option C:** This option is also incorrect as it does not match the condition where Magnan's symptom is observed.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that Magnan's symptom, or **formication**, is a critical diagnostic clue in patients with a history of **substance abuse**, particularly those using cocaine. Recognizing this symptom can help in identifying the underlying cause of the patient's condition.
**Correct Answer:** D. Cocaine addiction.