Human skin color is determined by melanin, the pigment which is produced by melanocytes in the epidermis (the top layer of the skin). A dark person has more melanin than a fair skinned person. Uneven skin tone is caused by uneven buildup of melanin. Dark parts of the skin, or hyperpigmentation, are the areas where too much melanin is produced while lighter parts, or hypopigmentation, are the areas where too little melanin is produced.
- Sun exposure: Excessive sun exposure stimulates melanocyte activity, resulting in an overproduction of melanin. Age spots and freckles are also caused by ultraviolet rays.
- Aging: As you age, cellular turnover slows down, causing a thick buildup of dead skin cells. Melanocyte regulation also becomes less controlled by the body. When you expose to the sun or develop scarring, the melanocytes are activated, leading to high concentration of melanin on the affected area.
- Oily skin: In oily skin, sebaceous glands produce excessive sebum (an oily matter that helps lubricate the skin). This causes dead skin cells to solidify and stick to the skin’s surface. This thick layer of dead skin cells appear as uneven patches of skin tone.
- Hormonal imbalance: Hormonal imbalances caused by pregnancy, birth control pills, or thyroid imbalance can lead to a hyper-pigmented skin condition called melasma. Fortunately, melasma often fades over several months after stopping oral birth control pills or after delivering a child.
- Skin problem: Vitiligo is a hypo-pigmented condition that creates white patches on the skin. Vitiligo happens because the immune system attacks the melanin-producing cells, resulting in skin pigmentation disorder.
- Skin inflammation: Uneven skin tone can be a result of post-inflammatory hyperpigmentation caused by acne lesions or scarring as well as irritation caused by shaving, ingrown hair, harsh skin care products, or chemical cosmetics. These scarring and irritation stimulate the melanin production.
- Dark skin: People with dark South Asian, Mediterranean, or African skin tones are likely to have uneven skin tone. When dark skin scars or becomes irritated, the scarring or irritation increases the melanin production, causing hyperpigmentation around the area. Light-skinned people may also have uneven skin tone if melanin under their skin is distributed unevenly.
- Vitamin deficiency: Deficiency of iron, calcium, vitamin A, E, and B complex can cause skin discoloration.
How to Even Your Skin Tone?
- Exfoliate regularly: Glycolic, lactic, and salicylic acids are great exfoliants that help remove dead skin cells from the outer layer of the skin. Exfoliate the skin twice to three times a week. You will get results in 3 – 4 weeks.
- Apply a topical vitamin A or Hydroquinone cream: A topical vitamin A (retinoids and retinols) blocks the production of melanin and gradually peels dark patches from the skin. Hydroquinone is an effective bleaching treatment for uneven skin tone. You will see an improvement of the skin tone after using the cream regularly for one to two months.
- Get in-office procedures: Microdermabrasion, chemical peels, or Intense Pulsed Light Therapy (IPL) can be performed by a dermatologist to even your skin tone. These procedures help remove the top layer of skin and reveal new, healthy skin underneath.
The Mayo Clinic mentions about several treatments for vitiligo, including topical psoralen plus ultraviolet A (PUVA), topical corticosteroid therapy, topical immunomodulators, depigmentation and narrowband ultraviolet B (UVB) therapy, oral psoralen photochemotherapy, as well as surgical procedures.
How to Prevent Uneven Skin Tone?
- Apply sunscreen: Use a sunscreen with broad-spectrum protection because it can prevent your skin from both UVA and UVB. Also, stay out of the sun between 10 am and 4 pm, when the sun’s rays are strongest.
- Eat healthily: Eat foods rich in vitamins to avoid the chance of vitamin deficiency. You should also drink a lot of water to keep the skin hydrated. Dehydration makes the uneven skin tone appear even worse.
- Treat oily skin properly: Use skin care products that are developed for oily skin to help control oils and remove buildup of oils from the skin. This also reduces the chance of developing acne and post-inflammatory hyperpigmentation.
- Use hypoallergenic makeup: This type of makeup products is less likely to cause allergic reactions on your skin.