Why does you hair itch when dye it?

1. Allergic reaction

One of the most common causes of itchy scalp after hair dye is an allergic reaction to the dye itself. This can happen even if you've used the same dye before without any problems. Over time, your body can develop an allergy to any of the chemicals in hair dye, including:

* Paraphenylenediamine (PPD)

* Toluene-2,5-diamine (TDA)

* Ammonia

* Hydrogen peroxide

2. Skin irritation

Hair dye can also irritate your scalp, even if you're not allergic to it. This is because the chemicals in hair dye can strip away the natural oils from your scalp, leaving it dry and irritated. Other potential irritants include:

* Fragrances

* Preservatives

* Emulsifiers

3. Contact dermatitis

Contact dermatitis is a type of skin inflammation that can be caused by coming into contact with an allergen or irritant. In the case of hair dye, contact dermatitis can be caused by any of the chemicals in the dye, even if you're not allergic to them. Symptoms of contact dermatitis include:

* Itching

* Redness

* Swelling

* Blistering

* Oozing

4. Folliculitis

Folliculitis is a condition that occurs when the hair follicles become infected. This can be caused by bacteria, fungi, or viruses. Folliculitis can be itchy, painful, and can sometimes lead to scarring.

5. Psoriasis

Psoriasis is a chronic skin condition that causes red, scaly patches of skin. It can affect any part of the body, including the scalp. Psoriasis can be itchy, painful, and can sometimes lead to hair loss.

If you're experiencing an itchy scalp after hair dye, it's important to see a doctor to determine the cause and get the appropriate treatment.

Tips for preventing an itchy scalp after hair dye

There are a few things you can do to help prevent an itchy scalp after hair dye:

* Do a patch test before using a new hair dye. This will help you determine if you're allergic to any of the chemicals in the dye.

* Choose a hair dye that is free of harsh chemicals, such as ammonia and peroxide.

* Apply a scalp protector before dyeing your hair. This will help to protect your scalp from the chemicals in the dye.

* Rinse your hair thoroughly after dyeing it. This will help to remove any residual dye that could irritate your scalp.

* Moisturize your scalp after dyeing it. This will help to soothe and hydrate your scalp.

* Avoid scratching your scalp, as this can make the itching worse.

If you experience an itchy scalp after hair dye, stop using the dye and see a doctor.