## **Core Concept**
The question describes a patient with a non-itchy plaque that is positive for hyphae, which suggests a fungal infection. Fungal infections can be caused by various types of fungi, including dermatophytes, yeast, and molds. The presence of hyphae is characteristic of dermatophyte infections and some yeast infections.

## **Why the Correct Answer is Right**
The correct answer, **. Tinea corporis**, is a type of dermatophyte infection that affects the skin of the body, excluding the hands, feet, face, scalp, and groin. It is characterized by well-defined, circular, or oval-shaped plaques that are typically non-itchy or mildly itchy. The diagnosis is confirmed by the presence of hyphae on microscopic examination of skin scrapings, which is a hallmark of dermatophyte infections.

## **Why Each Wrong Option is Incorrect**
* **Option A:** Psoriasis is a chronic autoimmune skin condition characterized by thick, scaly, red plaques, but it is not caused by a fungal infection and would not be positive for hyphae.
* **Option B:** Seborrheic dermatitis is a skin condition that causes scaly patches, red skin, and stubborn dandruff, but it is not typically associated with hyphae on microscopy.
* **Option D:** Candidiasis can present with erythematous plaques and is caused by yeast, but it more commonly affects moist areas of the body and may show both yeast and pseudohyphae on microscopy.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that tinea infections (including tinea corporis) are often diagnosed using the KOH preparation, where skin scrapings are treated with potassium hydroxide to dissolve cellular material and highlight fungal elements like hyphae. A positive result shows characteristic hyphae, supporting the diagnosis of a dermatophyte infection.

## **Correct Answer:** . Tinea corporis