How to test if your skin is sensitive to Cosmetics?

In this Article (Index)

• What is Sensitive Skin?
• What causes it?
• Link to microbes in the gut and skin
• Sensitized Skin
• How do you test for sensitive skin?
• Treating Sensitive Skin
• Tips for the Safe Use of Cosmetics

Learn about Skin Sensitivity

Skincare advice

What is Sensitive Skin?

Sensitive skin isn't a skin disease, it is a syndrome, a self-reported condition where those suffering from it recognize it by its nasty effects and its negative impact on their quality of life.

It affects roughly half of the world's population, and an analysis that looked into 26 studies in 18 countries found that roughly 70% of the population reported having "slight", "moderate" or "very" sensitive skin.

The outward symptoms of sensitive skin are tightness, tingling, burning sensation, stinging, pain and itch. Sometimes redness of the face may appear, and it can involve other parts of the body besides the face.

They main trigger are cosmetics because they contain potentially irritant ingredients. Household products may also affect the skin (cleaners and detergents) (1).

Formal Definition

The International Forum for the Study of Itch (IFSI) has defined this condition as follows:(3)

A syndrome defined by the occurrence of unpleasant sensations (stinging, burning, pain, pruritus, and tingling sensations) in response to stimuli that normally should not provoke such sensations. These unpleasant sensations cannot be explained by lesions attributable to any skin disease. The skin can appear normal or be accompanied by erythema. Sensitive skin can affect all body locations, especially the face. IFSI (2017)

Note on the terminology: Pruritus is itching and erythema is reddening.

It doesn't only affect women

More and more men are reporting sensitive skin on the face as they are using more cosmetics than in the past. Roughly 50 to 60% of men have some degree of sensitive skin (60-70% of women report the syndrome). So the gap between sexes is closing.

Causes of Sensitive Skin

It affects people of different cultures, ethnic origins and geographic locations, and is due to intrinsic genetic factors such as gender, hormones, stress, and skin type. These are then triggered by external factors such as irritant chemicals to provoke the painful effects of sensitive skin.

Sensitive skin syndrome can become worse due to external factors such as temperature (heat, cold), sunlight, dryness, wind, pollution, chemicals (soaps, deodorants, water, cosmetics), and allergies (2)

Possible biological mechanisms that provoke Sensitive Skin

Sensitive skin shows an alteration in the barrier function disrupting the fatty molecules that are located between the skin's cells.

There is also an abnormal activation of the nerve endings in the skin through some neuroreceptor proteins known as transient receptor potential or (TRP) that induce pain, itching and burning sensations like reported by those suffering from this syndrome (3) (4), but the actual mechanism that provokes the barrier damage and the hyperstimulation of the nerve endings is unknown.

Could the skin and gut microbiota be involved?

Seite & Misery (2018)(4) have suggested that the intestinal microbiota has an influence on the central nervous system and immunity, it is possible that it activates pro-inflammatory molecules known as cytokines and that these can affect the skin. They also reported that a clinical trial carried out in France found a link between Irritable Bowel Syndrome (IBS) and skin sensitivity where "irritable bowel syndrome was more frequent according to the severity of sensitive skin syndrome".

The skin supports a complex microbiota, the yeast and bacteria on our skin are influenced by its acidity (pH) and if it is oily, dry or moist and also by the prebiotics they find there. They produce chemicals (vitamin A, E, K and several B ones) as well as other conpounds that have an impact on the skin and in turn these bacteria are affected by some proteins released by nerve endings in the skin. The microbiota extends within the dermis allowing physical contact between bacteria an skin cells.

In people with healthy skin, the microbiota creates a protective environment, but when the skin barrier is disrupted or skin becomes dry it causes inflammatory responses and alters the protective relationship between the microbiota and the human host, it exposes nerve ends to external agents causing discomfort.

Research is ongoing, and still has to answer other questions such as: is sensitive skin a risk factor in developing chronic itch? is there a relationship with atopic dermatitis? Is it linked to underlying chronic inflammation? (3).

Asians are more sensitive

Knaggs (2009) (5) reports tgat Japanese and Chinese have greater irritation and a quicker onset of the reaction in comparison to Caucasians. It couldn't be explained with barrier function differences or a greater innnervation (density of nerves) in ths tissue. It is probably due to different skin permeability to irritating chemicals including pathways such as the greater number of sweat glands in Asians.

Sensitized Skin

We have seen that sensitive skin is one that for genetic or internal reasons is easily irritated causing discomfort when exposed to certain external triggers. Sensitized skin on the other hand is a normal skin that is temporarily irritated after being exposed to some external environmental factor.

There are hundreds of chemicals that induce skin sensitization that results in an allergic contact dermatitis or ACD.

The mechanism is the following: If a worker (sensitization is mainly an occupational health problem) is exposed to a sensitizing agent (allergen), it induces the activation of allergen-responsive T cells and sensitize the person to that allergen. The next time that worker is exposed to it, the site of contact will become temporarily red and inflamed, a reaction known as ACD (6).

How do you test for sensitive skin?

How to Test Skin Care Products

The American Academy of Dermatology Association provides the folloiwng tips to test a skin care product (8):

Even if you know your skin well, even if it is healthy, and not sensitive, is is possible that an ingredient in a cosmetic formulation may trigger an allergic contact dermatitis sensitizing it.

The trick is to test cosmetics on several small areas of your skin first, to see if you experience a skin reaction.

Skin Test

• Apply the product twice a day for 7-10 days in the normal amount you would use in a regular way.
• Choose a quarter-sized spot in a place where it won't get washed away (not on your hands) or rubbed off. For instance: the bend of your elbow, the underside of the arm.
• Leave it on for as long as it would be under normal use conditions. If it is a wash-off product, leave it for 5 minutes on your skin or as long as the instructions say.
• If you have no redness, itching or swelling after the trial period, you can use the product normally.

If you develop a negative skin reaction, wash the product off as soon as possible, do not use it again. Apply a cool compress or petroleum jelly to relieve your irritated skin. If the reaction is severe, see a dermatologist for treatment.

Treating Sensitive Skin

Inamadar and Palit (7) admit that there is no simple treatment for sensitive skin. They recommend selecting the right cosmetics for sensitive skins and following a two-week strategy

Adopt a "Two-week" strategy and discontinue all topical cosmetics and skin care products and switch form your regular soap to a Syndet soap, these are milder and better tolerated by people with sensitive skins than regular soap bars. Some people are sensitive to Syndet, so test it before using it.

Avoid sources of skin friction during this period and discontinue medicatins that cause dryness or may irritate such as tretinoin or benzoyl peroxide (anti-acne medications).

Make an appointment with your dermatologist, perhaps patch and photo-patch testing can pinpoint the sources of the allergic contact dermatitis.

Then you can gradually reintroduce your cosmetics one at a time (and one per week). Choose non-irritant cosmetics -based on your previous experience. Palit and Inamadar suggest:

• Powder cosmetics preferred
• Use cosmetics that are easily washed off with water
• Always use fresh cosmetics
• Purchase cosmetics products with less than 10 ingredients
• Use powder/cream formulations of facial foundations
• Use a sunscreen. SPF is fundamental, use physical sunscreen agents that sit as a shield on your skin instead of being absorbed. Zinc oxide ones are ideal and don't give you a ghost face
• Select fragrance free products

Test them on the skin in general as indicated further up, and then on a small part of your face (under your jaw for instance). Look out for any adverse reactions.

Tips for the Safe Use of Cosmetics

The FDA (9) (10) provides some tips for the safe use of cosmetics and some of them can help prevent sensitive skin triggers from touching your skin:

• Keep eye cosmetics clean in tight and closed containers, protected from sunlight and extreme temperatures. This will keep them from breaking down into potentially irritant chemicals and keep them free of microbes that can cause infections.
• Don't share or swap cosmetics, avoid testers at stores, they can contaminate products with germs. Use single-use applicators instead (clean cotton swabs).
• Read the Label. Check the ingredient declaration on the label, you may find one that you want to avoid or compare the ingredients of different brands. Avoid cosmetics without an ingredient declaration. Pay attention to directions and warnings.
• Things like eybrow tints, eyelash tints may have harmful chemicals. False eyelashes and eyelash extensions require adhesives to hold them in place and these may cause irritation to the sensitive eylid skin and the eye. Read the ingredient list on the adhesives.
• Throw them out after their expiry date or if there are changes in color, texture or smell.
• Don't use cosmetics near your eyes unless they are specially intended for eyes.
• Even though a lable says Hypoallergenic don't assume that the product will not cause allergic reactions.

The American Food and Drug Administration (FDA) has a resource that shows you How to Report a Cosmetic Related Complaint.