**Question:** Blephritis acarica is caused by-

A. Tarsal scabies
B. Demodex folliculorum
C. Mites
D. Human scabies

**Core Concept:** Blephritis acarica is a type of ocular inflammation and infection caused by mites (Acanthocheyla mendica), which are a type of mite found in eyelashes. Blepharitis refers to inflammation of the eyelids, whereas acariasis refers to an infection caused by mites.

**Why the Correct Answer is Right:** Blephritis acarica is caused by Acanthocheyla mendica, a specific type of mite. These mites are responsible for invading the eyelash follicles, leading to inflammation and infection. In comparison, option A (Tarsal scabies) refers to a different type of mite infection, while options B and D pertain to different types of mites causing skin infections, not ocular infections.

**Why Each Wrong Option is Incorrect:**

Option A (Tarsal scabies) refers to scabies caused by Sarcoptes scabiei, a different mite species that primarily affects the skin.

Option B (Demodex folliculorum) refers to Demodex mites, which are usually found on human skin but can occasionally cause blepharitis, not blephritis acarica.

Option D (Human scabies) is caused by Sarcoptes scabiei, a different mite species than the one causing blephritis acarica. Human scabies primarily affects the skin, while blephritis acarica specifically affects the eyelashes and eyelids.

**Clinical Pearl:** Blephritis acarica should be considered in the differential diagnosis of ocular inflammation, particularly in endemic areas, as it may present with symptoms similar to other ocular infections. Early diagnosis and treatment are crucial to prevent complications such as keratitis, corneal ulcer, and vision loss.

**Correct Answer:** C (Mites)