**Question:** Autoimmunity can be caused due to all of the following except-

A. Genetic factors
B. Environmental factors
C. Viruses
D. Medications

**Core Concept:**
Autoimmunity is a condition where the immune system mistakenly attacks the body's own cells and tissues, leading to inflammation, cell damage, and potentially tissue dysfunction or destruction. This process can be influenced by various factors, including genetic, environmental, viral, and medication exposure.

**Why the Correct Answer is Right:**
The correct answer, **D. Medications**, is right because some medications can trigger autoimmune reactions in genetically susceptible individuals. These medications are referred to as "drug-induced autoimmunity" or "drug-induced autoimmune reactions." However, medications are not a primary cause of autoimmunity in the general population.

**Why Each Wrong Option is Incorrect:**
A. Genetic factors: The concept of "autoimmunity is a disease of the genetically susceptible" highlights the importance of genetic predisposition in autoimmunity. While specific genes have been identified that increase the risk for autoimmune diseases, they are not the sole cause.

B. Environmental factors: Environmental triggers like infections, toxins, and diet can exacerbate pre-existing autoimmunity or influence the development of autoimmunity in susceptible individuals. However, they are not the primary cause of autoimmunity like genetic factors or medications.

C. Viruses: Viruses can trigger autoimmunity through molecular mimicry, bystander activation, or epitope spreading mechanisms, but they are not the primary cause of autoimmunity. Infections can exacerbate preexisting autoimmune conditions or influence the development of autoimmunity in genetically susceptible individuals.

**Clinical Pearl / High-Yield Fact:**
Autoimmune diseases are a group of more than 80 disorders characterized by immune system dysfunction. Some examples include Type 1 Diabetes, Rheumatoid Arthritis, and Systemic Lupus Erythematosus. Understanding the complex interplay between genetic, environmental, and other factors is crucial for diagnosing and treating autoimmune diseases effectively.