Epidermal hyperplasia reduction

Epidermal hyperplasia reduction is a clinical and histological endpoint describing the reversal of abnormal epidermal thickening, a condition known as acanthosis that is a hallmark of chronic inflammatory and hyperproliferative skin diseases such as psoriasis and atopic dermatitis (1, 4). This process involves the downregulation of excessive keratinocyte proliferation and the normalization of the differentiation program, which is often disrupted by pro-inflammatory cytokines (4, 9). While not a singular molecular target (e.g., a receptor or enzyme), it is the intended therapeutic outcome of drugs that inhibit signaling pathways driving skin expansion, such as the Interleukin-23 (IL-23)/IL-17 axis, Janus kinase/Signal Transducer and Activator of Transcription (JAK/STAT) signaling, and growth factor pathways including the Epidermal Growth Factor Receptor (EGFR) and Insulin-like Growth Factor 1 Receptor (IGF-1R) (2, 3, 6). Successful reduction of epidermal hyperplasia leads to the resolution of scaly plaques and restoration of skin barrier integrity (1, 5). Monitoring this effect is typically performed through skin biopsies or non-invasive imaging to measure changes in epidermal width and the expression of proliferation markers like Ki-67 (8, 10).

Other names

Acanthosis reductionEpidermal thickness reductionKeratinocyte hyperproliferation reversalEpidermal thinning

Reduction of epidermal hyperplasia is achieved through the therapeutic inhibition of key inflammatory and growth-promoting axes—most notably the IL-23/IL-17 and IL-4/IL-13 pathways—or the direct blockade of growth factor receptors (EGFR, IGF-1R) that stimulate keratinocytes to undergo excessive division.