Histopathological Features of Rosacea

Core Histopathological Findings

The inflammatory infiltrate consists predominantly of CD4+ T lymphocytes, along with contributions from macrophages, mast cells, and dendritic cells representing dysregulation of both innate and adaptive immune systems, according to the British Journal of Dermatology 1
Sebaceous gland hyperplasia characterizes phymatous changes, which along with cutaneous thickening and deformation represent the histological substrate for this diagnostic feature, as noted by Praxis Medical Insights 2

While these histopathological features are characteristic, rosacea remains primarily a clinical diagnosis based on persistent centrofacial erythema with periodic intensification or phymatous changes, as stated by Praxis Medical Insights 2
The histopathological findings reflect the underlying pathophysiology involving dysregulation of innate and adaptive immune systems, neurovascular abnormalities, and increased levels of antimicrobial peptides, neuropeptides, and inflammatory mediators, as reported by the British Journal of Dermatology and Praxis Medical Insights 1, 2