Commonest cause of epistaxis in children is
**Core Concept**
Epistaxis, or nosebleed, is a common condition in children often resulting from trauma or minor irritation of the nasal mucosa. The commonest cause of epistaxis in children is related to the unique anatomy of their nasal passages and blood vessels.
**Why the Correct Answer is Right**
The anterior nasal septum is richly supplied with small, fragile blood vessels that are prone to rupture. In children, the nasal septum is also more flexible and can be easily traumatized, leading to bleeding. The correct answer is **Dry Air**, which is a common cause of epistaxis in children due to the dry air's ability to irritate and dry out the nasal mucosa, making it more susceptible to bleeding.
**Why Each Wrong Option is Incorrect**
* **Option A:** Allergic Rhinitis is not typically a cause of epistaxis in children. While allergic rhinitis can cause nasal congestion and discharge, it is not typically associated with bleeding.
* **Option B:** Nasal foreign body is a potential cause of epistaxis in children, but it is not the most common cause. Foreign bodies can cause trauma to the nasal mucosa, leading to bleeding.
* **Option D:** Septal perforation is a potential complication of recurrent epistaxis, but it is not a cause of epistaxis in children.
**Clinical Pearl / High-Yield Fact**
Children with epistaxis may also have dry, cracked lips and a history of recent exposure to dry air, such as from a heater or air conditioner.
**Correct Answer: A. Dry Air**