What is a common symptom of a client allergic to a hair dye?

A client who is allergic to hair dye often exhibits symptoms such as redness, itching, or rash in the area where the dye was applied. This localized reaction occurs as the body's immune system responds to the allergens present in the dye. Skin irritation is a direct indication of an allergic response, and these symptoms can manifest shortly after the application of the product.

Other symptoms, although they may be associated with various hair or scalp conditions, are not as distinctly linked to an allergic reaction to hair dye. For instance, headaches and dizziness can be attributed to other factors and may not directly relate to the chemical components of hair dye. Similarly, hair loss or thinning is typically influenced by a range of factors, including genetics and overall health, rather than solely by an allergic response. Excessive dryness of the scalp may result from various treatments or environmental conditions, but it does not specifically indicate an allergic reaction. Thus, the presence of redness, itching, or rash is the most clear-cut sign indicating a possible allergy to hair dye.