Dermatophytoses in caused by –
**Core Concept**
Dermatophytoses, also known as ringworm, are fungal infections that affect the skin, hair, and nails. These infections are caused by a specific group of fungi known as dermatophytes, which are obligate parasites that obtain their nutrients by breaking down keratin, a protein found in skin, hair, and nails.
**Why the Correct Answer is Right**
Dermatophytes infect the stratum corneum of the skin, causing inflammation and tissue damage. The most common dermatophytes responsible for infections in humans are Trichophyton, Microsporum, and Epidermophyton species. These fungi use enzymes such as keratinase to degrade keratin, leading to the characteristic symptoms of dermatophytoses, including scaly patches, itching, and inflammation.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because dermatophytoses are not caused by protozoa.
**Option B:** This option is incorrect because bacterial infections, such as impetigo or cellulitis, are different from dermatophytoses.
**Option C:** This option is incorrect because viral infections, such as herpes simplex or varicella, are not the same as dermatophytoses.
**Clinical Pearl / High-Yield Fact**
It's essential to note that dermatophytoses can be spread through direct contact with an infected person or animal, contaminated surfaces, or by sharing personal care items. Treatment typically involves topical or oral antifungal medications, such as terbinafine or itraconazole.
**Correct Answer: D. Dermatophytes. Fungal infections caused by dermatophytes.**