**Question:** All of the following are true about episcleritis except-

A. Episcleritis is a non-inflammatory condition of the sclera.
B. Episcleritis is a manifestation of systemic disease.
C. Episcleritis is a result of ocular surgery.
D. Episcleritis is a type of corneal ulcer.

**Core Concept:** Episcleritis is a condition characterized by inflammation of the episclera, the outer layer of the sclera, which lies between the sclera and the conjunctiva. It is usually a manifestation of a systemic disease or an adverse reaction to medications.

**Why the Correct Answer is Right:**

1. Episcleritis is a non-inflammatory condition, and option A is incorrect because it describes episcleritis as a non-inflammatory event. Inflammation is a key feature of the condition, making it distinct from non-inflammatory conditions like scleritis.

2. Episcleritis is a manifestation of systemic disease, which is supported by option B being correct. It often occurs as a result of an underlying systemic disorder affecting the blood vessels or immune system, such as rheumatoid arthritis, thyroid disorders, or collagen vascular diseases.

3. Episcleritis is not related to ocular surgery (option C), as it is an idiopathic disorder, meaning it has no apparent cause.

4. Episcleritis is not a type of corneal ulcer (option D), as corneal ulcers are infectious or traumatic injuries to the cornea, whereas episcleritis affects the episclera.

**Why Each Wrong Option is Incorrect:**

1. Episcleritis is a manifestation of systemic disease (option B), making it distinct from scleritis, which is an isolated ocular inflammation.
2. Episcleritis is not related to ocular surgery (option C), as it occurs spontaneously and is idiopathic, meaning it has no apparent cause.
3. Episcleritis is not a type of corneal ulcer (option D), as corneal ulcers are infectious or traumatic injuries to the cornea, while episcleritis affects the episclera.

**Core Concept:** Episcleritis is a benign condition with a relatively good prognosis if diagnosed and treated promptly. It is often associated with systemic diseases or adverse reactions to medications, making it essential for physicians to consider episcleritis in patients presenting with ocular inflammation.

**Clinical Pearls:**

- When examining patients with episcleritis, physicians should consider systemic diseases and drug reactions as potential underlying causes.
- Episcleritis is a benign condition with good prognosis if treated promptly.
- Involvement of the conjunctiva in episcleritis is uncommon.

**Why Each Wrong Option is Incorrect:**

1. Episcleritis is often associated with systemic diseases (option B) or drug reactions (option C), making it distinct from scleritis, which is typically a primary ocular inflammation.
2. Episcleritis rarely involves the conjunctiva (option D). While conjunctival involvement is possible, it is