As the National Day holiday approaches, many people are arranging beauty treatments for their trips - hair styling, manicures, and eyelash extensions - the complete beauty trio. But do you know the hidden risks involved?

Recently, the topic "Sun Yi's facial swelling caused by hair dyeing" became a trending topic on Weibo. Similarly, 23-year-old Xiao Tang (pseudonym) was also hospitalized due to hair dye allergies.

Xiao Tang is a devoted "fan girl" who often imitates her idol's appearance and frequently dyes her hair. Not long ago, when her idol switched to an ash gray hair color, Xiao Tang immediately dragged her best friend to a salon to "replicate" the same style.

The next day, she noticed many pinpoint-sized red spots on her calves that didn't hurt or itch, so she didn't pay much attention. However, a few days later, she suddenly experienced severe stomach pain accompanied by nausea and vomiting, and was rushed to the hospital.

Test results showed that Xiao Tang had occult blood in her urine and 3+ urine protein. Combined with her frequent hair dyeing history and the symmetrically distributed, non-blanching red spots on her legs, doctors diagnosed allergic purpura caused by hair dyeing that had affected her digestive tract and kidneys, requiring immediate hospitalization.

Could hair dyeing really be this dangerous?

**Hair Dyeing Has 3 Major Risks**

**1. Allergies** Components like para-phenylenediamine (PPDA) in hair dyes may cause skin allergies. If mild symptoms occur during hair dyeing, such as redness, swelling, itching, burning pain, blistering, or discharge on the head and face, stop dyeing immediately and wash thoroughly. Severe cases can cause systemic skin allergies and even be life-threatening, requiring immediate dermatological treatment.

**2. Hair Damage** Frequent hair dyeing may make hair more fragile and prone to breakage. Hair may also become dull, rough, and split, resembling dry grass.

**3. Heavy Metal Poisoning** Hair dyes are permitted to contain certain amounts of heavy metals like mercury and lead. However, some unregulated, poor-quality hair dyes may contain excessive amounts of heavy metals. Long-term repeated use of such products may cause heavy metal poisoning.

**"Dangerous Components" in Hair Dyes**

Commercial hair dyes (especially permanent ones) typically contain: - **Para-phenylenediamine (PPD)**: Helps colors adhere permanently but is highly allergenic. The EU has limited its concentration (≤2%). - **Hydrogen peroxide**: Bleaches natural pigments but may damage scalp barriers. - **Ammonia**: Opens hair cuticles for dye penetration, but its pungent odor can cause respiratory discomfort. - **Heavy metals (like lead, arsenic)**: Some low-cost products may illegally add these neurotoxic substances.

**Who Should Avoid Hair Dyeing?**

■ **People with sensitive scalp and skin** Since para-phenylenediamine in hair dyes is highly allergenic, it may cause skin itching, allergies, dermatitis, and blisters.

■ **People with damaged skin** Those with damaged skin, eczema, ulcers, or broken skin should not dye their hair, as chemicals from hair dyes can enter through wounds and cause skin irritation.

■ **Pregnant and breastfeeding women** These women are not recommended to dye their hair because: 1) increased sensitivity during pregnancy raises allergy risks, and 2) during breastfeeding, chemicals from hair dyes entering the body may pass through breast milk, potentially accumulating harmful substances in fetuses and children, affecting their health.

■ **Elderly and those with poor liver/kidney function** These groups have weaker detoxification abilities, making it difficult to metabolize chemicals that enter the body, increasing disease risk.

**How to Dye Hair Safely**

First, purchase hair dyes from legitimate manufacturers. Qualified hair dye products must be approved. Domestic hair dyes should display "国妆特字年份第XXX号" and imported ones should show "国妆进字年份第XXX号."

Second, conduct a patch test before dyeing. Apply a small amount of hair dye behind the ear or on the inner wrist, observe for 48 hours. If no redness, itching, rash, or systemic discomfort occurs, it's safe to use.

Third, ensure scalp health. If there are wounds or skin inflammation on the scalp, postpone hair dyeing to prevent irritation and dye penetration. During dyeing, protect facial and behind-ear skin, avoid excessive contact with hair dye on scalp and other body parts, and rinse thoroughly afterward to prevent residue.

Fourth, those with allergic tendencies should be especially cautious when choosing hair dyes.

Extensive information and precise analysis available in Sina Finance APP