Erythema

Erythema, commonly known as redness, is a clinical manifestation and physiological symptom characterized by the reddening of the skin or mucous membranes. This discoloration primarily results from the dilation of superficial blood vessels and increased regional blood flow (hyperemia) in response to stimuli such as inflammation, physical trauma, infection, or immune system activation [15, 17]. Although redness is not a singular molecular target (e.g., a specific receptor or enzyme), it is a vital phenotypic endpoint and clinical biomarker used to evaluate the severity and therapeutic response of various dermatological and systemic conditions, including rosacea, psoriasis, and dermatitis [11, 12, 18]. Therapeutic strategies to manage redness involve targeting the biological pathways that regulate vascular tone and inflammatory signaling, such as activating alpha-adrenergic receptors to induce vasoconstriction or inhibiting pro-inflammatory mediators like cathelicidins and toll-like receptor 2 (TLR2) [1, 9, 13]. Redness serves as a key parameter in both diagnostic assessments and the clinical development of anti-inflammatory and vascular-acting medications [11, 20].

Other names

ErythemaFacial rednessSkin flushingHyperemiaRubor

The clinical reduction of redness is typically achieved through vasoconstriction via alpha-1 and alpha-2 adrenergic receptor agonism (e.g., brimonidine, oxymetazoline) or by modulating inflammatory cascades such as the TLR2-KLK5-LL37 axis and the NLRP3 inflammasome [1, 9, 13, 18].