Demelanizing Agents - Lighten Your Skin

What Are Demelanizing Agents?

Demelanizing agents, also known as depigmenting agents, lighten the dark patches on the skin. These skin-lightening agents can be used to treat hyperpigmentation as they interfere with the various steps involved in synthesizing melanin and reducing dark patches. Depigmenting agents may be classified based on their interfering mechanism to regulate melanin synthesis.

What Are Demelanizing Agents Used For?

Demelanizing agents are used primarily for skin disorders associated with hyperpigmentation. The drug may be used to reduce discolored patches seen in melasma. It is often prescribed for treating vitiligo, characterized by large patches of skin with loss of color. These agents may be used in post-inflammatory hyperpigmentation marks after chemical peels, laser treatments, or after a bout of acne. It can reduce tan spots or freckles caused by sun exposure. Demelanizing agents can treat brown or grey patches that often appear on the cheeks and nose due to hormonal changes during pregnancy. Specific agents, generally plant extracts, are used in cosmetics, facial moisturizers, and hair conditioners. Demelanizing agents can be used as a single component or with combinations of other demeaning agents, such as skin-whitening agents. Some of the commonly used examples of depigmenting agents are Hydroquinone, Mequinol, azelaic acid, Monobenzone, Tretinoin, and ascorbic acid.

How Do Demelanizing Agents Work?

Demelanizing agents inhibit tyrosinase, which is responsible for the first step in melanin production. Demelanizing agents are available as a cream to be applied topically. The cream should be stored at room temperature.

What Are the Commonly Used Demelanizing Agents?

Some of the commonly used examples of depigmenting agents are

1. Hydroquinone Mequinol

These are used to reduce pigmentation of the skin. Topical hydroquinone and mequinol usually result in temporary skin-lightening. They work by inhibiting the conversion of dopamine to melanin by inhibiting the enzyme tyrosinase.

Uses:

• 2 % to 6 % lotion for treatment of melasma and chloasma. The pigmentation recurs when it is discontinued. Care should be taken to avoid contact with the eyes.

Adverse Effects:

• Skin irritation.

• Allergy.

• Sclera and nail pigmentation.

• Loss of skin elasticity.

• Impaired wound healing.

• Ochronosis (a disorder characterized by blue-black pigmentation).

2. Monobenzone

Monobenzone is a derivative of hydroquinone and a potent demelanizing agent. It acts by destroying the melanocytes and causing permanent depigmentation. The whole effect is visible in four to six months.

Uses:

• Widespread vitiligo.

• Post-inflammatory melasma.

• 5 % lotion or 20 % ointment is applied twice a day.

Side Effects:

• Irregular, ugly depigmentation patches.

• Erythema.

• Eczema.

• Local irritation.

3. Azelaic Acid

Azelaic acid is a dicarboxylic acid isolated from the Pityrosporum ovale. The agent inhibits the melanin-forming enzyme tyrosinase. It is a weak depolarizing agent with reversible hypopigmentation and antimicrobial properties. Azelaic acid is used as a 10 % and 20% cream.

Uses:

• Acne.

• Papulopustular rosacea.

• Melasma.

Adverse Effects:

• Local irritation.

4. Corticosteroids

Topical steroids whiten the skin by initial blanching due to vasoconstriction. However, this results in slow cell turnover and reduces the activity and production of melanocytes.

Uses:

• Acne

• Acne rosacea.

Adverse Effects:

• Adrenal suppression.

• Worsening of untreated infections.

• Irreversible thinning of the skin.

• Perioral dermatitis.

• Contact dermatitis.

5. Mequinol

Mequinol is also a 4-hydroxyanisole and methoxy phenol and is a competitive tyrosinase inhibitor. The drug is available as 2 % of a prescription product.

Uses:

• Skin-lightening

Adverse Effects:

• Local irritation.

6. Tretinoin:

Tretinoin is a topical retinoid used in many skin whitening products. It reduces pigmentation by inhibiting tyrosinase induction, interferes with pigment transfer, and accelerates epidermal turnover. In addition, retinoids act as penetration enhancers with other whitening agents like hydroquinone and mequinol.

Uses:

• Skin-whitening.

• Inflammatory lesions in mild to moderate acne.

Adverse Effects:

• Burning.

• Stinging.

• Erythema.

• Dryness.

• Scaling of the skin.

• Hyperpigmentation in dark-skinned people.

• Tretinoin is a prescription medicine and should not be used in pregnancy because of the potential risk of adverse events.

7. Ascorbic Acid

Ascorbic acid and its derivatives are used as an antioxidant. It can reduce o-dopaquinone to dopa and inhibit melanin formation. In addition, the antioxidant has a protective effect against skin damage caused by ultraviolet irradiation. Daily application of a cream with a 10 % ascorbic acid derivative can produce a significant whitening effect in patients with melasma.

Uses:

• Antioxidant.

• Skin-whitening.

• Melasma.

Adverse Effects:

• Ascorbic acid can increase free radicals with traces of metal ions.

8. Mercury-Containing Compounds

Mercury deactivates the enzyme that produces melanin and may be used for skin whitening. Long-term use darkens skin and nails as mercury deposits in the epidermis and hair follicles.

Uses:

• Skin-whitening.
• Adverse Effects:
• Mercury poisoning.

9. Fruits - Certain fruits, such as papaya, have an enzyme called papain that can whiten the skin. Other fruits with similar effects include vitamin C, such as lemon, lime, and orange.

10. Combination of Demelanizing Agents - Combination therapies have more efficacy when compared to monotherapy, such as

• Hydroquinone is used in combination with steroids to help to reduce the side effects of Hydroquinone. The addition of sequential glycolic acid treatment with Hydroquinone enhances drug penetration.

• Some other vital combinations used for skin-lightening effects include Azelaic acid 20 % and Tretinoin 0.05 % or 0.1 %. Hydroquinone 5 %, Tretinoin 0.1 %, and Dexamethasone 0.1 %. Hydroquinone 2 %, Kojic acid 2 %, and glycolic acid 10 % in a gel.

What Are the Side Effects of Demelanizing Agents?

Common after-effects of demelanizing agents may include,

• Burning.

• Itching.

• Stinging.

• Dryness.

• Erythema (redness of the skin).

• Localized contact dermatitis (blistering, scaling, dry skin, and swelling of treated sites).

• Loss of color from areas away from the area of application.

The rare side effects include

• Blue-black pigmentation of the skin.

• Fingernail staining.

• Hypersensitivity reaction.

What Precautions Need to Be Taken When Using Demelanizing Agents?

• Allergies - It is recommended to avoid demelanizing agents if you have had allergic reactions to any one of its ingredients.

• Pregnancy and Breastfeeding - Hydroquinone and other depigmenting agents should be used cautiously during pregnancy and breastfeeding.

• Asthma - Treatment with demelanizing agents should be done with caution in people with a history of asthma and other predisposing conditions.

• Elderly - Using demelanizing agents such as those containing mercury may cause serious neurological and kidney problems in older adults and should be used with caution.

• Children - Depigmenting agents can cause irritant dermatitis, numbness, and memory loss and should be used cautiously.

Conclusion:

Demelanizing agents lighten hyperpigmented patches on the skin. They help to brighten the skin and protect against sun damage. It is, however, recommended to have a healthy diet that includes fruits, vegetables, low-fat meat, and dairy products for healthy skin.