Sun Spots Explanation: Understanding Why Skin Exhibits White Marks After Sun Exposure
Sun exposure, even on overcast days, can lead to various skin conditions, particularly changes in skin pigmentation. These changes often manifest as white spots, patches, or discoloration collectively referred to as "sun spots." However, the precise nature of these pigment changes can signify different skin conditions.
Dermatologist Christine Poblete-Lopez, MD, outlines some common pigment-related conditions and offers advice on avoiding or reducing their occurrence.
Pigmentation Disorders and Sun Exposure
Your skin, comprising about 19 million skin cells and 60,000 melanocytes, produces melanin, the skin pigment. The amount of melanin determines your skin color. Hyperpigmentation, or the increase in melanin, makes the skin appear darker, while a lack of melanin leads to lighter skin.
Prolonged sun exposure can influence the production of melanocytes, potentially leading to various pigmentation disorders that may be affected by sun exposure or tanning. Tanning may also heighten the risk for all forms of skin cancer, particularly melanoma.
Distinct Conditions
direct sun exposure can result in sunburns, which can be painful and bothersome. Sun exposure can also cause freckles due to concentrated melanin in small areas. However, white spots or patches stem from a lack of pigment, differing from freckles and sunburns.
Sun Spots
Sun spots, also known as idiopathic guttate hypomelanosis, appear as small, white dots or raindrops on the skin, most often on areas exposed to the sun, such as the arms, legs, and lower body. These white spots occur because of reduced pigmentation in the affected region. Although troubling aesthetically, they are not a sign of worsening conditions and predominantly appear painless and non-itchy.
Tinea Versicolor
Overproduction of yeast on the skin causes tinea versicolor, a common fungal skin infection. Unlike sun spots, this condition appears in larger, less defined patches, often on the chest, back, or face. Affected areas may show up as lighter colors for those with darker skin or as faint, light brown spots for those with pale skin. This condition is often associated with excessive sweating because yeast feeds on sweat.
Vitiligo
Vitiligo is a chronic autoimmune condition in which inflammatory cells target and destroy melanocytes, the cells responsible for creating skin pigment. This condition affects lighter areas of the skin and may be exacerbated by sunburn because sun-exposed areas lacking pigment are more vulnerable. Vitiligo typically begins in early childhood and may be associated with other autoimmune diseases such as lupus.
Pityriasis Alba
Pityriasis alba is believed to be caused by post-inflammatory hypopigmentation associated with eczema. It causes lighter, wider patches on the cheeks of children and sometimes adults with eczema. Inflammation from eczema causes scaly, itchy rashes, which tend to fade to white or gray pigmentation once the eczema is treated. To control the inflammation associated with pityriasis alba, doctors use topical steroids or nonsteroidal anti-inflammatory topical creams.
When to Consult a Doctor
Always pay attention to any changes in your moles, birthmarks, pimples, or bruises on your body, and consider annual skin cancer screenings if you have a history of melanoma, frequently use tanning beds, have blistering sunburns, significant regular sun exposure, or are an organ transplant recipient. Although white sun spots may not pose additional dangers, consult a dermatologist should you notice any changes in your skin tone to ensure your safety.
Dr. Poblete-Lopez emphasizes the importance of sun protection, particularly for those with pigmentation problems, as areas without pigment cells are more vulnerable to developing skin cancers.
Protecting Your Skin from the Sun
Though complete shade from the sun may not always be achievable, taking precautions can help minimize sun exposure. These include daily use of moisturizers with sunscreen, wearing sun-protective clothing, and donning wide-brimmed hats. As Dr. Poblete-Lopez suggests, develop the habit of using sun protection much like you brush your teeth.
- Hyper-awareness of one's skin is crucial, as changes in moles, birthmarks, pimples, or bruises could signify underlying medical conditions, and annual skin cancer screenings may be beneficial for those with a history of melanoma, frequent tanning bed use, blistering sunburns, significant regular sun exposure, or organ transplant recipients.
- Sun protection is of utmost importance, especially for individuals with pigmentation problems, as areas lacking pigment cells are more susceptible to skin cancers. Adopting daily habits such as applying moisturizers with sunscreen, wearing sun-protective clothing, and donning wide-brimmed hats can help minimize sun exposure.
- Dermatologist Christine Poblete-Lopez advises that areas of reduced pigmentation, such as those seen in sun spots or various medical conditions like vitiligo, are more vulnerable to skin cancers.
