A 2-month-old infant presents for an examination with a diffusely erythematous macular rash in the diaper area. What is the most likely cause of this rash?

The most likely cause of a diffusely erythematous macular rash in the diaper area of a 2-month-old infant is indeed associated with contact dermatitis. This condition commonly arises from prolonged exposure to moisture, friction, or irritants in the diaper area, such as urine and feces. The characteristics of contact dermatitis include a well-defined border and the presence of erythematous patches, often accompanied by some scaling or vesicles.

Babies have sensitive skin, and their diapered areas are particularly prone to irritation. The rash can present quickly and may resolve with appropriate management, including regular diaper changes and barrier creams to protect the skin. Understanding these patterns is crucial for differentiating from other skin conditions in infants.

While other options can cause rashes in infants, their presentation and locations differ. For example, Candida albicans infections typically result in a more erythematous rash with satellite lesions and may occur in the folds of the skin rather than being diffusely macular across the diaper area. Eczema often appears as dry, scaly patches and usually has a history of atopy, while seborrheic dermatitis, often seen on the scalp, presents as greasy, yellow scaly areas rather than a classic diaper rash. Knowing