Skin discolouration is a common condition that can be caused by a number of reasons, from heavy sun exposure to autoimmune diseases to allergies and hormonal changes. Some causes are more widespread and normal compared to others, but even minor discoloration colouring should be looked at by a doctor or dermatologist to determine what’s triggering it and how to treat it. Read on to learn more about the most common conditions and potential causes that lead to skin discoloration.


Eczema is one of the most common skin conditions that cause skin discolouration. Approximately 17 percent of Canadians will suffer from this condition at some point in their life, and in the US, over 30 million people ( 10.1 percent of the population) have some form of eczema. Though there are several types of eczema, it generally causes inflamed, cracked and itchy patches of skin that can feel rough, leaving a reddish colour on the skin. People of all ethnicities and skin colours can develop this condition. It can be triggered by the immune system, as well as certain foods like dairy and nuts. Pollen, fragrances, smoke and other environmental triggers can set it off too. Eczema usually surfaces during childhood and can remain into adulthood for some, whereas others can outgrow it. 

Although there is no known treatment for this skin condition, there are some things that can help to reduce and alleviate the symptoms. This includes:

  • Learning about your triggers and avoiding them
  • Using mild soaps and cleansers that are fragrance-free
  • Wearing soft fabrics
  • Getting skincare treatments to soothe and hydrate the skin

Even if the condition subsides, it’s important to continue to take precautions and good care of your skin to avoid flare-ups and inflammation.


Another skin condition that’s quite common is melasma, also known as chloasma, which forms darker patches along the skin. Though the actual cause of this isn’t quite known, certain things have been shown to trigger it, including pregnancy, stress, birth control pills, sun exposure, hormone therapy and in some cases, thyroid disease. Women are at a much higher risk of developing it, especially pregnant women and those with darker skin tones.

Similar to eczema, melasma can naturally disappear over time, especially when it’s triggered by birth control pills and pregnancy. In some cases, melasma can be greatly improved and lightened by certain skin treatments like chemical peels, dermabrasion, and microdermabrasion since they essentially strip away the top layers of the skin. For long-term results, repeat skin treatments such as these could be necessary to reduce flare-ups from returning. Also, it’s highly recommended for anyone suffering from this condition to avoid sun exposure as much as possible since UV rays can impact skin cells and pigmentation.

Heavy Sun Exposure

Heavy sun exposure can result in skin discolouration and is probably more normal and widespread than most. Since the sun’s UV rays directly impact pigmentation, it can quickly lead to sunburns and discoloured skin patches. Medications can also make the skin more sensitive to the sun, leaving it more vulnerable to sun damage. Sun exposure can exacerbate many skin conditions too, including the ones mentioned above. This is why dermatologists and skincare specialists always implore their patients to load up on the sunscreen whenever they are stepping outside and wear a hat or avoid exposure during the peak hours of the day. Simple habits such as these can go a long way in reducing patchy skin in addition to many other noticeable and serious skin conditions.

Autoimmune Diseases and Allergies

People suffering from certain autoimmune diseases, or even allergies, may experience skin discolouration. Aside from eczema, which is considered both an autoimmune disease and allergy, lupus and Graves’ disease have also been known to cause reactions that can range from skin darkening, lightening or blisters and rashes.  

Hormonal Changes

Many skin-related changes occur with hormonal changes and imbalances. Hormones fluctuate greatly during pregnancy as estrogen and progesterone levels increase. As a result, many skin conditions and discoloration are most common among women who are pregnant.

Other Causes

Medications, reactions to certain chemicals, ulcers and radiation therapy are other known and common causes of skin discoloration. 

If you’re suffering from skin discolouration, always talk to your doctor or dermatologist to learn what’s causing it and which treatments can help to alleviate or reduce the symptoms. If they recommend skin treatments that have proven to benefit and ease discolouration, book an appointment with one of our qualified skin specialists. At the Ottawa Skin Clinic, we offer advanced treatments, including chemical peels, photo facials, and micro-needling, specifically designed to target skin conditions like discolouration. To learn more about our services and how they can benefit your skin, contact us today to book a consultation.