What are benign, keratin-filled cysts located just under the epidermis called?

Milia are small, benign cysts that contain keratin and are typically found just beneath the epidermis. They are often white or slightly yellow and can appear anywhere on the skin, although they are most commonly found on the face, particularly around the eyes. These cysts form when keratin, a protein that helps protect the skin, becomes trapped in small pockets beneath the skin's surface. Milia are particularly common in newborns but can occur in individuals of any age. Their benign nature means they usually do not require treatment unless a cosmetic concern arises, and they may resolve on their own over time.

In contrast, nodules are larger, solid masses that can be benign or malignant and typically extend deeper into the skin. Macules are flat, discolored spots on the skin that do not have raised edges and are often associated with conditions like freckles or spots from sun exposure. Lesions refer to any abnormal area of tissue, including cuts, wounds, or growths, and the term is more general, encompassing a variety of skin conditions.