Dark Skin and Tropical Sun: A Often Ignored Risk

Title: Dark Skin and Tropical Sun: A Often Ignored Risk
Author: Jean-Marie St Cyr
Date: Sun, 02/11/2025 - 14:00

In tropical regions, many believe that dark skin is naturally "protected" from the sun. However, ultraviolet radiation remains a real danger. Sunburns, age spots, premature aging, and skin cancers also threaten individuals with higher phototypes, who are often insufficiently informed.

The color of the skin depends on the amount of melanin it contains. This pigment absorbs ultraviolet (UV) rays and partially protects against sun-related cellular damage. Consequently, certain misconceptions persist about dark skin. Dr. Shabneez Nawoor, a dermatologist at Dr. A. G. Jeetoo Hospital, explains, "Darker skin, which is richer in melanin, is therefore more resistant than lighter skin." However, this natural protection is not absolute. In tropical regions, prolonged exposure without precautions can lead to sunburn, premature skin aging, and skin cancers. Contrary to popular belief, UV rays do not disappear when the sky is cloudy. Depending on their thickness and position relative to the sun, 50 to 90% of ultraviolet rays can penetrate clouds. In Mauritius, even on gray days, prolonged exposure remains harmful. The consequences range from superficial burns to more serious conditions such as basal cell carcinoma (a small shiny nodule or persistent sore), squamous cell carcinoma (scaly plaques or open sores), or melanoma, the most dangerous form of skin cancer. UV rays also promote premature skin aging and certain eye conditions, such as cataracts.

When to Consult a Dermatologist?

Skin blemishes or lesions should not be taken lightly. To identify a suspicious anomaly, the ABCDE rule remains a simple guideline, emphasizes Dr. Nawoor:
A for asymmetry;
B for irregular borders;
C for multiple colors;
D for diameter greater than 6 mm;
E for evolution (changes in shape, color, or size).

"At the first sign of any of these, consult a dermatologist, who can perform a thorough examination and a biopsy if necessary," she indicates. Early diagnosis significantly improves healing chances.

Cancers Often Detected Late

Among individuals with dark skin, skin cancers are less common but are often diagnosed at an advanced stage, notes the dermatologist. The causes include a lack of awareness and the fact that lesions sometimes appear in areas less exposed to the sun, such as palms, soles of the feet, or under the nails. These unusual locations often delay detection and complicate management. Therefore, regular self-examinations of the skin and medical consultation at the slightest doubt are essential.

The Role of SPF for Darker Skin Types

Contrary to another misconception, sunscreen (SPF) remains essential, even for dark skin. It reduces the risks of burns, hyperpigmentation, premature aging, and cancer. Dermatologists recommend a broad-spectrum sunscreen with an SPF of at least 30, to be applied 15 minutes before exposure and reapplied every two to four hours.

Good Daily Practices

To effectively protect oneself in a tropical climate, the dermatologist recommends using a broad-spectrum SPF 30 or higher sunscreen. It’s also advisable to wear covering, light-colored clothing and to use a wide-brimmed hat and UV-filtering sunglasses. To avoid sunburn, it’s better to avoid exposure between 10 AM and 3 PM, when rays are most intense. Another imperative is never to expose infants under six months to direct sunlight. "Even on cloudy days, vigilance is necessary. In a country like Mauritius, where the sun shines almost all year round, prevention remains the best protection," emphasizes Dr. Nawoor.

Skin Cancers: Prevent Before It's Too Late

Skin cancers, often linked to excessive sun exposure, remain frequent even among dark-skinned individuals. Dermatologists and oncologists emphasize the importance of prevention, vigilance, and protection against UV rays.

Dr. Khevin Bujhawon, an oncologist, explains that there are different types of skin cancer: melanoma, basal cell carcinoma (BCC), or squamous cell carcinoma. In most cases, these cancers are linked to excessive sun exposure. "Protected or less exposed areas of the body have a reduced risk," he adds.

Although lighter skin is more vulnerable, especially after prolonged sun exposure, Dr. Bujhawon points out that the sun is not the only factor. Exposure to artificial ultraviolet rays, used in some tanning devices, can also cause skin damage. "When UV rays penetrate the skin, they destroy epidermal cells and cause DNA mutations, leading to cancer," he adds.

The oncologist recommends avoiding direct sun exposure between 10 AM and 2 PM and staying in the shade as much as possible. If one must go out, he advises applying sunscreen with a minimum SPF of 30, or even 50, and wearing loose clothing covering the body. As Dr. Shabneez Nawoor also reminds us, even on cloudy days, UV rays penetrate clouds and continue to pose a risk.

Dr. Bujhawon stresses the late diagnosis of skin cancers due to their diverse forms. BCC can develop beneath the skin and remain less visible. Melanoma forms beneath the epidermis and is often only detected when a lesion appears. Squamous cell carcinoma manifests as a sore that many mistakenly take for a trivial injury, thereby delaying diagnosis.

Skin cancers primarily affect sun-exposed areas: the scalp, face, backs of hands, and feet. They can manifest as a lump, a sore that doesn't heal, or a dark spot that rapidly changes in size or color. Some lesions go unnoticed due to their location, further delaying diagnosis.

"The more we protect ourselves from UV rays, the lower the risk of developing skin cancer," emphasizes Dr. Bujhawon, highlighting the importance of prevention and vigilance.