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Why do cells in the stratum corneum lose their nuclei as they reach the skin surface?

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skin rash caused by Lyme disease — skin disease Visible alterations in the texture of the skin, such as rashes and hives, can be indicative of serious disease. For example, one of the first signs of Lyme disease is a circular rash in a bull's-eye pattern on the skin.

The cells in the stratum corneum, known as corneocytes, lose their nuclei and most other organelles as part of the terminal differentiation process of keratinocytes as they move from the granular layer to the skin surface.1

This transition is a fundamental aspect of epidermal development. As these cells progress peripherally from the living malpighian layer, they undergo a transformation where they become progressively flattened and filled with keratin. By the time they reach the stratum corneum, the cells are essentially dead, having shed their nuclei, organelles, and keratohyalin granules. This process allows the cells to become specialized, keratin-packed structures that, along with an extracellular matrix of lipids, form a protective, water-resistant barrier for the body. Ultimately, these cornified cells are desquamated, or shed, from the skin surface.123