Allergic contact dermatitis from cosmetics is the #1 reason people get patch tested for skin allergies. Your face is ground zero because it gets exposed to the most products—especially your eyelids, which can react to everything from mascara to shampoo rinsing down. Where the rash shows up (eyelids, sides of face, center, or all over) actually tells you which product is likely the culprit.
This is a comprehensive review of allergic contact dermatitis research, examining patterns in how cosmetics trigger skin reactions and where those reactions appear on the face.
Funding not disclosed in abstract