Which of the following skin diseases is known to be caused by a fungus?

Ringworm is known to be caused by a fungus, specifically dermatophytes, which are a type of mold. This condition can affect various parts of the body, including the scalp, skin, and nails, leading to circular, itchy, and often red patches on the skin. The term "ringworm" can be misleading as it does not involve any actual worms; rather, it refers to the ring-like appearance of the lesions caused by fungal infection.

Understanding the nature of ringworm highlights the importance of proper diagnosis and treatment, as antifungal medications are typically required to resolve the infection effectively. Distinct from other skin conditions, ringworm necessitates specific antifungal therapies, making it crucial for both practitioners and patients to recognize its fungal origin.

In contrast, eczema is primarily an inflammatory skin condition often linked to allergies or irritants, psoriasis is an autoimmune disease characterized by rapid skin cell production, and scabies is caused by a mite infestation, none of which are fungal infections. This clear distinction reinforces the unique nature of ringworm as a fungal disease.