Fragrance Shampoos: Scalp Itch Culprit?

Fragrances in shampoos are a common cause of scalp irritation and can trigger allergies and even asthma attacks. An allergy to fragrance is the most common type of skin allergy and is the leading cause of cosmetic contact dermatitis. The fragrances in shampoos can cause an allergic reaction, resulting in redness, itching, swelling, and blisters on the scalp or neck. In some cases, a more severe reaction, such as anaphylaxis or hives, may occur. Therefore, it is important to determine whether your itchy scalp is caused by an allergy to fragrance shampoo and to take appropriate action, such as switching to fragrance-free shampoo.

Fragrance sensitivity and allergic reactions

Fragrance Sensitivity

Fragrance sensitivity occurs when your airways are irritated by ingredients or chemicals in natural or manufactured scents. It can happen to anyone but is more likely if you have asthma or allergies. Symptoms include a ticklish feeling in your nose, a raw or burning sensation in the nasal passages, and watery, itchy, or red eyes. These symptoms tend to be worse the longer the exposure or the stronger the scent.

Allergic Reactions

Allergic reactions occur when certain fragrance components called allergens come into direct contact with the skin. This causes the immune system to react by making protective proteins called antibodies to defend against the allergens. This inflammatory response leads to allergy symptoms.

In most cases, the reaction results in allergic contact dermatitis (ACD), an itchy rash that shows up on the skin that has been directly exposed to the irritating substance. Other symptoms include hyperpigmentation (patches of skin that are darker than usual), swelling, burning, or tenderness.

Diagnoses and Treatments

The best way to diagnose a fragrance sensitivity or allergy is to undergo skin patch testing. This involves placing patches with allergens on the skin of your arm or back and wearing them for 48 hours.

Treatments for fragrance sensitivity or allergy include avoiding offending fragrances, over-the-counter oral antihistamines, and over-the-counter topical steroid creams.

Common fragrance allergens

Fragrances are often added to hair care products to give them a pleasant scent or mask an unpleasant smell. However, they are a common cause of scalp irritation and can trigger allergic reactions.

The European Commission has identified 26 fragrance ingredients listed as allergens in Annex III of the European Union Cosmetics Directive. These include:

• Amyl cinnamal (also known as Jasmonal A)
• Amyl cinnamyl alcohol
• Butylphenyl methylpropional (Lilial)
• Hexyl cinnamal (Jasmonal H)
• Hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC) or Lyral
• Evernia furfuracea (Treemoss) extract
• Evernia prunastri (Oakmoss) extract

These substances are required to be listed in the ingredients of cosmetic products under the Cosmetic Regulation. However, it can be challenging to identify specific fragrance chemicals in products, as they may be listed generally as "fragrance" or "perfume" without specifying the individual ingredients.

In addition to causing allergic contact dermatitis, fragrance ingredients can also affect the respiratory system, particularly in individuals with asthma, allergic rhinitis, or viral respiratory infections. Inhaling fragrances may result in shortness of breath, a sensation of suffocation, coughing, phlegm, a runny or stuffy nose, headaches, chest tightness, and wheezing.

Other common shampoo allergens

Shampoos can contain a number of allergens, including fragrances, preservatives, and certain chemicals used for cleansing and lathering. While some people may not experience any adverse effects, others may be sensitive to these ingredients and develop an allergic reaction. Here are some other common shampoo allergens that may cause an itchy scalp:

Cocamidopropyl Betaine

This is a surfactant, which is a cleansing and lathering agent, and is one of the most common allergens present in shampoos. It can cause skin irritation and allergic contact dermatitis, which is characterised by itchy, red skin.

Methylchloroisothiazolinone and Methylisothiazolinone (MCI/MI)

These are common preservative systems used in liquid personal care products like shampoos. They are also known to cause skin irritation and allergic reactions.

Formaldehyde Releasers

Many hair products use formaldehyde releasers as preservatives. Some examples include Bronopol, Diazolidinyl Urea, and DMDM Hydantoin. These chemicals can also lead to allergic reactions and skin irritation.

Parabens

Parabens are used as preservatives in shampoos to prevent microbial growth. However, they are common allergens that can cause skin irritation and allergic reactions, particularly for those with a history of eczema or skin allergies.

Sulfates

Sulfates are another type of surfactant used in shampoos for their cleansing and lathering properties. They can irritate the skin and scalp, leading to itching and even allergic reactions in sensitive individuals.

If you suspect that your itchy scalp is due to an allergy, it is important to consult a dermatologist or healthcare provider for proper diagnosis and treatment. They may recommend patch testing to identify specific allergens and advise you on choosing hypoallergenic or fragrance-free shampoos.

Symptoms of an allergic reaction

Allergic reactions to shampoo can cause a variety of symptoms, ranging from mild to severe. Here are some common symptoms of an allergic reaction to fragrance shampoo:

Redness or Irritation:

The skin on the scalp or neck becomes inflamed and red. This is often one of the first signs of an allergic reaction.

Itching or Burning Sensation:

Allergens in fragranced shampoos can cause an intense itching or burning sensation on the scalp. This is a common symptom of an allergic reaction.

Swelling or Puffiness:

The skin around the scalp or neck may swell, leading to puffiness. This is caused by the body's immune reaction to the allergen.

Blisters or Bumps:

Small blisters or raised bumps may form on the scalp in more severe reactions. This indicates a strong immune response to the allergen.

Dryness or Peeling:

Prolonged exposure to allergens in fragranced shampoos can lead to dryness, flaking, or peeling of the scalp, similar to dandruff. This can be uncomfortable and unsightly.

Sun Sensitivity:

The affected skin area may become extremely sensitive to sunlight, resulting in heightened redness, burning, and skin peeling when exposed to the sun.

Hives or Anaphylaxis:

In extreme cases, an allergic reaction to shampoo can lead to hives—raised, red welts on the skin. Anaphylaxis, a life-threatening reaction, may also occur, causing difficulty breathing, swelling in the throat, or dizziness.

It is important to note that symptoms of an allergic reaction to fragrance shampoo can vary from person to person and may appear within minutes to hours of exposure. If you experience any of these symptoms, stop using the product immediately and consult a healthcare professional.

Treatment for allergic reactions

Fragrances are often added to hair care products to give them a pleasant scent. However, they are one of the leading causes of allergic reactions. If you are experiencing an itchy scalp, it is a good idea to see your dermatologist to find the cause.

If you experience an allergic reaction to a hair-care product, stop using it immediately and switch to mild shampoos/conditioners that do not contain fragrances. A non-irritating shampoo can help soothe and calm an itchy scalp.

• Rinse the area with water and stop using the product.
• Apply mild hydrocortisone cream or calamine lotion or take an antihistamine to reduce symptoms.
• For more severe cases of allergic contact dermatitis, your provider may prescribe a topical steroid cream, or a systemic steroid medication.
• If the reaction is severe or the cause isn't clear, consult a healthcare provider or allergist who can recommend allergen-free shampoos.

Frequently asked questions