Name a common allergic reaction symptom in skincare.

Redness or rash on the skin is a common symptom of an allergic reaction in skincare. When an individual experiences an allergic reaction, the immune system responds to a substance it deems harmful, leading to inflammation. This inflammation often manifests as redness, swelling, or a rash on the affected area of the skin.

Other phenomena, such as smoothness, increased elasticity, and a radiant glow, are generally considered positive outcomes related to healthy skin or effective skincare treatments, rather than indicators of a reaction. Recognizing redness or a rash as a symptom is essential for skincare professionals to ensure they can identify allergies or sensitivities and advise clients appropriately.