**Membranous Conjunctivitis Core Concept**
Membranous conjunctivitis is an inflammatory condition characterized by the formation of a membrane or pseudomembrane on the conjunctiva, typically due to an infectious or allergic cause. This condition often presents with symptoms such as redness, swelling, and discharge.

**Why the Correct Answer is Right**
Membranous conjunctivitis is usually caused by viral infections such as the common cold or herpes simplex virus, but can also be triggered by bacterial infections like gonorrhea or chlamydia. The formation of the pseudomembrane is a result of the body's immune response to the infection, which involves the activation of various inflammatory cells and the release of cytokines. The exact pathophysiology can vary depending on the underlying cause.

**Why Each Wrong Option is Incorrect**
* **Option A:** Incorrect. Membranous conjunctivitis can indeed be caused by bacterial infections, including gonorrhea and chlamydia.
* **Option B:** Incorrect. The condition is not typically associated with an autoimmune response, but rather an infectious or allergic cause.
* **Option C:** Incorrect. While some cases of membranous conjunctivitis may be severe, it is not typically a life-threatening condition.

**Clinical Pearl / High-Yield Fact**
One key point to remember about membranous conjunctivitis is that it can be a complication of other underlying conditions, such as conjunctivitis or keratitis, and may require prompt medical attention to prevent long-term damage to the eye.

**Correct Answer: D.**