Before Dyeing Your Child's Hair: Risks Parents Should Know

Health authorities and dermatologists caution parents against treating hair dye as a harmless cosmetic product for children. Some dyes, particularly permanent and semi permanent formulas, can irritate the scalp or trigger allergic reactions, while repeated bleaching can leave hair dry, fragile and more likely to break.

One of the ingredients most strongly associated with hair dye allergies is paraphenylenediamine, or PPD, which is found in many permanent and some semi permanent hair dyes. Reactions can include itching, redness, burning and swelling, and repeated exposure can lead to increased sensitivity in some people.

European Union rules covering a number of oxidative hair dye ingredients require labels warning that the products are not intended for people under 16 and that hair colourants can cause severe allergic reactions. Parents should therefore check the label carefully rather than assuming a product is suitable for a child simply because it is widely available or comes in bright colours.

Bleaching the hair before applying a lighter or brighter colour can add another source of damage. The American Academy of Dermatology says lightening hair by several shades generally requires stronger peroxide concentrations, which can increase dryness, weakness and breakage.

For a temporary colour change, parents can avoid permanent dyes and strong bleaching products where possible and look instead for washable temporary products that are specifically labelled as appropriate for the child's age. Ingredient lists and age instructions should still be checked because temporary products can also cause irritation or allergic reactions.

The U.S. Food and Drug Administration advises consumers to follow product directions carefully, perform the recommended skin test before using hair dye, never leave dye on longer than instructed and rinse the scalp thoroughly afterward. Dye should also be avoided when the scalp is irritated, sunburned or damaged.

Extra caution is needed if a child has previously reacted to hair dye or to a temporary "black henna" tattoo. Black henna may contain PPD and can increase the risk of an allergic response during later exposure to hair dye.

If significant burning, itching, redness or swelling develops during or after dyeing, the product should be stopped and the hair and scalp thoroughly washed. Difficulty breathing or swelling of the tongue or throat can signal a severe allergic reaction and requires emergency medical attention.