Which of the following is true of dendritic ulcer –a) Caused by Herpes simplex virusb) Topical corticosteroid given suppresses the symptomsc) Oral acyclovir is effective in treatmentd) Topical acyclovir is effective in treatmente) Heals spontaneously

**Core Concept**
Dendritic ulcers are a type of corneal ulceration caused by the reactivation of herpes simplex virus (HSV) in the trigeminal nerve ganglion, leading to inflammation and ulceration of the cornea.

**Why the Correct Answer is Right**
The correct answer is **a)** Caused by Herpes simplex virus. Dendritic ulcers are a classic manifestation of herpes simplex keratitis, a condition where the herpes simplex virus infects the cornea, causing characteristic branching ulcers. This is due to the reactivation of latent HSV in the trigeminal nerve ganglion, which then spreads to the cornea via the ophthalmic branch of the trigeminal nerve. The virus infects the epithelial cells of the cornea, leading to inflammation and ulceration.

**Why Each Wrong Option is Incorrect**
* **Option B:** Topical corticosteroids can actually worsen dendritic ulcers by suppressing the immune response and allowing the virus to replicate further.
* **Option C:** Oral acyclovir is effective in treating herpes simplex keratitis, but it is not the preferred treatment for dendritic ulcers, which are typically managed with topical antiviral medications.
* **Option D:** Topical acyclovir is effective in treating dendritic ulcers, but this option is not the correct answer because it is not the only true statement among the options.
* **Option E:** Dendritic ulcers do not heal spontaneously and require prompt treatment with antiviral medications to prevent scarring and vision loss.

**Clinical Pearl / High-Yield Fact**
Dendritic ulcers are a classic sign of herpes simplex keratitis, and prompt recognition and treatment are essential to prevent vision loss and scarring.

**Correct Answer:** a) Caused by Herpes simplex virus