What is a common symptom of allergic conjunctivitis?

Itchy, tearing eyes with a cobblestone appearance are hallmark symptoms of allergic conjunctivitis. This condition results from an allergic reaction, often triggered by allergens such as pollen, pet dander, or dust mites. The body's immune response to these allergens leads to inflammation and irritation of the conjunctiva, which is the membrane covering the white part of the eyeball and the inner eyelids.

The symptoms of allergic conjunctivitis are primarily characterized by intense itching, which is a direct result of histamine release, leading to further tearing and watery discharge as the eyes attempt to flush out the allergen. The “cobblestone” appearance refers to the swelling of the conjunctiva, which can develop into small raised bumps that resemble cobblestones, commonly seen upon examination.

In contrast, other symptoms associated with eye conditions may not align with the typical presentation of allergic conjunctivitis. For instance, painful eye redness and purulent discharge suggest bacterial conjunctivitis or other infectious causes. Scanty mucoid discharge can occur in various conditions but does not capture the characteristic extreme itching and watering indicative of an allergic process. Thus, the unique combination of symptoms aligned with option C makes it the appropriate choice for this question.