Polymorphic light eruption is thought to be caused by UV light altering a substance in the skin, which the immune system reacts to, resulting in the skin becoming inflamed. It's not passed down through families, but about 1 in 5 people with the condition have an affected relative as it's a fairly common condition.
That extra melanin is what creates a suntan. But sometimes skin doesn't make melanin evenly. As a result, the skin's coloring, called pigmentation, looks patchy. The sun also can cause small blood vessels to stretch, giving skin a blotchy look.
The exact cause of polymorphous light eruption isn't understood. The rash appears in people who have developed sensitivity to sunlight, especially ultraviolet (UV) radiation from the sun or other sources, such as tanning beds. This is called photosensitivity. It leads to immune system activity that causes a rash.
Heat rash develops when a duct that leads from a sweat gland to the surface of the skin is blocked or inflamed. This then blocks the opening of the sweat duct on the surface of the skin (sweat pore). Instead of evaporating, sweat is trapped beneath the skin, causing irritation and bumps on the skin.
Causes of sun allergy include immune system reactions to sunlight, certain medications and chemicals that make the skin more sensitive to the sun. It isn't clear why some people have a sun allergy and others don't. Inherited traits may play a role.
Pellagra, due to vitamin B3 (niacin) deficiency usually presents initially with photosensitivity.
While UVB exposure suppresses immune responses in healthy individuals, it is a well-described trigger of skin manifestations in numerous autoimmune diseases including systemic and cutaneous lupus erythematosus (SLE, CLE), dermatomyositis (DM), and Sjogren's syndrome (SS).
Autoimmune and connective tissue disorders that can lead to mottled skin include: Dermatomyositis. Fibromyalgia. Lupus.
Leukemia rashes appear as tiny red spots or purple areas that do not fade when pressed; these are caused by low platelet levels and the rupture of very small blood vessels in the skin. These spots are also known as petechiae or purpura, depending on their size.
The rash can take many different forms (polymorphic): you may get crops of 2mm to 5mm raised, pink or red spots, but redness may be harder to see on brown and black skin. some people get blisters that turn into larger, dry patches – it looks a bit like eczema.
The most effective treatment for sun allergy is avoiding sun exposure. Antihistamines such as loratadine, fexofenadine and cetirizine. Corticosteroids such as prednisone.
Current research shows that vitamin B6 supplementation may increase the skin's sensitivity to UV light, thus increasing the risk of skin cancer. If you are concerned about photosensitivity and currently take vitamin B6, talk with your doctor about reducing or eliminating this supplement to see if it helps your skin.
Keratinisation. Initially, UV rays do help dry out the surface layer of the epidermis, and with it the P. acnes bacteria responsible for acne. This is known as keratinisation of the skin, which comes with a hardening of the skin cells.
Sun rashes, also known as sun allergy or photodermatitis, are skin reactions triggered by exposure to sunlight. They can show up as red, itchy bumps, blisters, or patches of inflamed skin. These rashes typically occur within minutes to hours of sun exposure and can persist for days.
Most Sunspots (often known as “liver spots” though they have nothing to do with your liver) fade somewhat over time. They typically do not disappear completely because the skin has been permanently damaged by the sun. Sunspots are flat areas of discolored skin that can be tan or varying shades of brown.
Stage 1 – A patient has high levels of white blood cells and enlarged lymph nodes. Stage 2 – A patient has high levels of white blood cells and is anemic. He or she may also have enlarged lymph nodes. Stage 3 – A patient has high levels of white blood cells and is anemic.
People with iron deficiency anemia may experience itchy skin (pruritus) that can become red, bumpy and sore when scratched. Rashes associated with aplastic anemia usually appear as tiny red or purple dots under your skin (petechiae). The dots can form large patches but aren't usually itchy or painful.
Skin lesions associated with vitamin B12 deficiency are skin hyperpigmentation, vitiligo, angular stomatitis, and hair changes. Cutaneous lesions that do not respond to conventional therapy can be an indication of vitamin B12 deficiency. Malabsorption is the most common cause of vitamin B12 deficiency.
Blotchiness and uneven skin tone can be due to many factors including sun exposure and heredity. You may see red, white or dark patches on your skin. These blotchy patches of skin may become more visible when dead surface skin is not regularly exfoliated.
Many experience an increase in lupus symptoms after being exposed to ultraviolet (UV) rays, either from the sun or from artificial light. Photosensitive people may develop a skin rash, known as a butterfly rash, which appears over the nose and cheeks after sun exposure. Other rashes might look like hives.
Mineral sunscreens are a game-changer for people with autoimmune diseases. They contain zinc oxide or titanium dioxide. These ingredients sit on the skin's surface, acting as a shield against the sun. This means they're less likely to cause irritation.
Some dermatologists suggest that dietary supplements containing beta carotene, nicotinamide (vitamin B3), selenium, and probiotics can help to lessen outbreaks of polymorphous light eruption. These should be taken for one month before initial sun exposure, and throughout the duration of exposure.