Which condition is characterized by red, scaly, itchy skin on the feet?

The correct condition characterized by red, scaly, itchy skin on the feet is tinea pedis, commonly known as athlete's foot. This condition is a fungal infection that affects the skin on the feet, particularly in the spaces between the toes and on the soles. It is typically characterized by the aforementioned symptoms, which arise due to the growth of fungi in warm, moist environments often found in shoes and sweaty feet. The redness and scaling are indicative of the body’s inflammatory response to the fungal infection, which contributes to the intense itchiness associated with this condition.

The other conditions listed are different skin issues that may have some overlapping symptoms but are distinct in their causes and presentations. Psoriasis is an autoimmune condition that results in thick, silvery scales and can occur anywhere on the body, not specifically on the feet. Eczema, or atopic dermatitis, typically appears on the flexural areas of the body, causing red, inflamed, itchy patches that may not necessarily be scaly. Dermatitis is a general term for inflammation of the skin and can encompass a variety of conditions, including contact dermatitis, which results from contact with irritants or allergens and does not specifically describe the fungal infection seen in tinea pedis.