Why Does My Scalp Itch When I Use Hair Oil?

Hair oils are all the rage, thanks to their nourishing and deeply moisturizing properties. Jojoba oil, for example, is known to soften hair, and coconut oil can heal and strengthen damaged locks. For most people, oils don't come with any harmful side effects. If you do experience irritation, redness or itchiness, there are a few possible explanations.

If a hair oil seems to be causing issues, like a rash that appears up to two days after use, you might be having an allergic reaction to ingredients in the product. Some products contain allergenic chemicals like paraphenylenediamine, glyceryl thioglycolate and ammonium thioglycolate. Avoid these irritants and stick to pure hair oils without additives.

Certain shampoos and hair oils may cause contact dermatitis, with symptoms of redness and irritation. This condition isn't contagious or life-threatening—discontinue use of the product and the rash should resolve itself in two to four weeks. To reduce inflammation and alleviate the itch in the meantime, apply anti-itch creams or a wet compress to the irritated area. See a doctor if the rash continues beyond two to four weeks.

Hair products may be aggravating an existing condition of the scalp. Dry scalp skin—caused by frequent hair washing with hot water, aggressive shampoos or holding the hair dryer too close to the skin—is vulnerable to irritation and infection because it lacks the normal protective oil layer. Hair that isn't washed at least once a week can cause a buildup of skin cells, leading to itchiness and dandruff.

If a certain type of hair oil causes irritation to the scalp, stop using it. To treat the issue, there are a few options:

• Use a pH-balanced shampoo.
• Massage olive oil into the scalp 10 minutes before shampooing.
• Take antihistamines.

If the itching does not cease within a week, it's time to make an appointment with a dermatologist.