What is a common allergic reaction to skin care products?

Contact dermatitis is the correct choice as a common allergic reaction to skin care products. This condition occurs when the skin comes into direct contact with an allergen or irritant, leading to inflammation, redness, itching, and in some cases, blisters or swelling. Ingredients found in various skin care products, such as fragrances, preservatives, or certain active ingredients, can trigger this type of response in sensitive individuals.

Other conditions listed, like psoriasis, are chronic autoimmune skin diseases characterized by red, scaly patches and do not typically result from allergic reactions to skin care products. Eczema, while it can be confused with contact dermatitis, primarily stems from a combination of genetic and environmental factors rather than a direct allergic response to a specific product. Alopecia refers to hair loss and is not associated with allergic reactions to skincare, as it involves different underlying mechanisms. Thus, contact dermatitis distinctly represents an immediate allergenic response, making it the most fitting answer in this context.