Pigmentation: Causes and Chemistry

Florence Barrett-Hill
Skin conditions that affect the normal way in which melanin lies in the skin, such as chloasma, have always been of concern to clients and skin treatment therapist alike. The plethora of skin whitening & lightening products has also been a minefield to navigate.

Because UVR is the prime aggravating factor in relation to pigmentation and photo aging, this must always be addressed, so my mantra is always: “Establish cause of a pigmented skin condition before deciding what the treatment strategy will be.” 

This article may clarify some of the burning questions we ask:

  • Can skin lighting products work in the summer? 
  • What are the contra-indications? 
  • Are these products beneficial for skin aging? 
  • Can they be used on coloured skins?  
  • How long will it take before my client gets a result? 
  • How do skin lightening products work? 
  • What active works best? 
  • Would a combination of actives work? 
  • How important is a sunscreen in the formulation?
medication
Some medications can cause photo-sensitivity

To understand how any formulations for skin lightening work and why pigment conditions like chloasma exist, we must first understand how the pigment melanin is formed.
Common causes of pigmentation are:

  • Physical trauma
  • Chemical trauma
  • Contraceptive pill
  • Pregnancy
  • UVR (always)
  • Adrenal stress
  • Medications like Chlorpromazine will reduce burn time.

Commonly found and known photo-sensitisers:

  • Fragrances or Fragrance fixative or ingredients: Peru balsam, benzoyl alcohol, benzoyl salicylate, canga oil, cinnamic alcohol, geraniol, hydroxycitronellal, mithoxycitronellal, oak moss, musk, xylol, 6-methyl coumarin, cinnamic aldehyde.
  • Essential Oils: Jasmine absolute, lavender oil, red zig, sandalwood oil, ylang ylang oil, bergamot, lemon, lime, orange, mandarin, juniper.
  • Antiseptics/Disinfectants: Hexachlorophene, bithionol, 5-bromo-4-chlorsalicyanilide, chlorhexidine, chloro-2phenyphenol, triclocaran.
  • Sunscreen chemicals: Glyceryl-paminobenzoate, 2-hydroxy-4-methoxy-benophenone, isoamyl-p-N, Ndimethylaminobenzoate, p-methoxy-isoamyl-cinnamate,

There are a number of strategies that have been pursued by all cosmetic houses to control melanogenesis; this market has been one of the biggest growing sections of the beauty industry.

The following strategies have shown the best results so far:

  • Block the synthesis or processing of tyrosinase or inhibit its activity, so that melanogenisis can be prevented.
  • Be an endothelin antagonist, inhibiting cell communication between keratinocyte & melanocyte.
  • Have a high anti free radical profile to prevent sun damage.
  • Contain a broad-spectrum sun block to prevent UVA & UVB stimulation of all steps involved in melanogenisis.
  • To create melanin degradation.

Because of problems that came from the first whitening products such as mercury compounds (now prohibited) researchers have been looking for de-pigmenting materials in extracts from plants, microbes and mushrooms. Hundreds of natural herbs have been tested for effective tyrosinase inhibition, or related effect, many have shown great promise.

Melanogenesis can be driven by free radicals, it was thought that free radical scavengers might inhibit melanogenesis. It is these thoughts that have led to the biggest breakthroughs, and combination treatment creams offering high anti-free radical profiles with tyrosinase inhibitors plus a sun screen factor have proven to be the most effective in the fight against hyper-pigmentation.

  • Ascorbyl Magnesium Phosphate (Vit C): Has shown to offer both anti free radical & tyrosinase inhibitor effects.
  • Mulberry Extracts: An effective anti-free radical profile, it also offers a tyrosinase inhibitor effect.
  • Licorice Extract: Offers the greater tyrosinase inhibitor effect along with some potential to absorb UVA & UVB but this is not conclusive.
  • Arbutin: An extract of Bearberry has shown a high anti-free radical effect, but no tyrosinase inhibitor effect.
  • Green Tea Extract: Has shown to have a high anti-free radical effect.

Summary of Melanogenesis.

UV: Primarily responsible for triggering all the following steps in melanogenesis.

POMC: Propiomelanocortin, formed by the pituitary gland and the precursor to the melanin-stimulating hormone (MSH).

MSH: Melanin stimulating hormone adheres to receptor proteins (keratinocytes & melanocyte).

Tyrosinase: The enzyme behind the tan.

Tyrosine: The amino acid behind the tan.

L Dopa & Dopa Phosphates: Regulator & building blocks for the pigment melanin.

Melanocyte: The cell responsible for making the melanosome.

Melanocyticdendrite: Dendrite for melanosome transfer to keratinocyte.

Melanin: Pigment responsible for the colour of the skin, phaemelanin (red) Eumelanin (brown)

Keratinocyte: Cell responsible for transferring the pigment melanin up to the stratum corneum.

Endothelin: Increased melanogenisis in the melanocyte by proliferating melanocytes and boosting tyrosinase.

Systemic drugs: Tiaprofenic acid, carprofen, promethazine, chloropromazine.

Acne medication: Benzoyl peroxide, retinoic acid, unbuffered and very low or high pH glycolic acid, tretinoin, resorcinol.

Prescription drugs known to temporarily reduce burn time when taken: Antibiotics, anti-fungal, some blood pressure medication, steroids.

Offering ‘Environmental Defense Facial Treatment Programs‘ is a professional responsibility that all therapists must be aware of. (Also refer to “Seasonal appropriate treatments” and “Environmental Defense”.)

Autumn to spring salon treatment program:
This would concentrate on remove, repair and skin lightening, using products that have high concentrations of de-pigmenting actives. The ionisation of Vit C and the use of the new lactic peels would be a good start.

Autumn to spring take home care program:
Anti-free radical profile day creams and serums. Skin lightening serums & creams. A lower spf sunblock, used in conjunction with Vit C serums. Night creams should concentrate on cellular membrane repair and have high concentrations of essential fatty acids.

These and many more plant extracts offer one or a combination of melanogenesis inhibiting effects and anti-free radical ability. Used on their own or in combination, we now have an excellent range of products that seem to be effective against hyper-pigmentation. Showing less side effects than the older hydroquinone based lighteners. However unless used in combination with some broad-spectrum sun screen factor, may prove to be less effective than hoped.

Because UVR is the prime aggravating factor in relation to pigmentation and photo-aging this must always be addressed.

Establishing cause of the pigmented skin condition plays a big role in the known effectiveness of any skin lightner, this is the therapists first priority before embarking on a treatment plan. If the established cause of the pigmentation is induced by medication, either topically applied or orally taken i.e. corticosteroids or the contraceptive pill, no guarantee of improvement can be made, until the medication has been discontinued.

There are a number of well known chemicals that aggravate or cause hyper-pigmentation, but research has brought to light products commonly used by skin treatment therapists and clients that also are now known to photo-sensitisers.

Diagnosing photo-allergy
Photo-allergy is a delayed t-cell mediated immuno-reaction, resembling but not identical to, allergic contact dermatitis (ACD). A photo-reaction between a chemical (photo-sensitise) and UVR causes the photo-allergic response.

Although ACD is more common, photo-allergic reactions have become increasingly prevalent over recent decades. This is probably due to increased sun exposure during leisure time and an increasing number of photo-sensitising substances.

I think its important to note that some of these reactions are isolated cases and not common, especially with sun screens, others like undiluted essential oils and medication are always likely to happen. I have not been able to list all known chemicals the list is too long, what I have tried to do is give a broad spectrum view of the mine field you have to traverse when establishing cause.

It has been found with most skin lightening products that diligence in application must have first priority. A conscious effort must be made to avoid all natural and artificial UVA & UVB. A broad-spectrum sunscreen must be worn at all times (no exceptions).

It has been found with all skin lightening products that diligence in application must have first priority.
A conscious effort must be made to avoid all natural and artificial UVA & UVB.
A broad spectrum sunscreen must be worn at all times. (no exceptions)
The skin treatment therapist must plan a one year treatment program for her client, using the seasons as her guide.

Spring to Autumn salon treatment program:
Offer your client “environmental defense” salon treatments throughout the entire spring and summer. These would have a high anti-free radical profile using the Vit C’s etc.

Spring to Autumn take home care program:
Determine the clients burn time, and select the spf that will give her optimum protection for high risk exposure. In addition select a lower spf for those times when exposure is not so high risk. An anti-free radical profile serum that will be applied under the sun screen and at night under her treatment cream.