Psoriasis
Other factors are less common but also cause scalp itching, including psoriasis . This is an autoimmune disease that causes red patches and scales.
Contact dermatitis
Dr. Chacon also mentions contact dermatitis , an allergic reaction or irritation linked to hair products, particularly hair dye or shampoo. “Read product labels and know what to look for,” advises Dr. Anna Chacon. She specifically points to sulfates, parabens, alcohol, perfumes, and synthetic dyes—substances that can cause itching, especially if you already have sensitive skin or a scalp condition.
“If you notice any of the ingredients listed above, especially among the first ones listed on the label (indicating a higher concentration), you should perhaps consider alternative products. For those with sensitive skin or those prone to scalp irritation, opt for products labeled as hypoallergenic, for sensitive skin, or all-natural,” recommends the specialist, who advises doing a patch test before using a hair product for the first time : spread the product on the inside of your forearm and leave it for a full day. If you experience irritation or itching in this area, do not use the product.
