Autoimmune diseases are a type of condition in which the body’s immune system begins to attack and terminate healthy cells and tissues within the body. In a properly functioning immune system, white blood cells protect the body from foreign agents such as bacteria and viruses, through producing antibodies to locate and destroy them. However, in autoimmune disease patients, the body is unable to differentiate between healthy cells and attacking viral or bacterial agents. This results in white bloods cells indiscriminately destroying any other types of cells.
Many autoimmune diseases affect the skin: noticeably changing coloring, moisture and photosensitivity. As the A.D.A.M. Medical Encyclopedia puts it, “the underlying cause of autoimmune diseases is not fully known.” In fact, the causes of many skin-related conditions are still relatively unknown, as well. We’ve taken a look at one autoimmune disorder, as well as two skin-related disorders associated with autoimmune and genetic dysfunctions, in order to examine what part sun exposure plays in the development of their symptoms.
Vitiligo itself is not classified as an autoimmune disorder. It is a condition that directly affects the melanocytes: cells that create pigments and color in the skin. This pigmentation disorder destroys the melanocytes: creating bleached looking white patches on the skin – on any part of the body – while also showing up on mucous membranes (including the inside of the mouth and nose), as well as the retina. Hair around effected areas may also turn white, as a result.
Approximately 0.5 to 1% of the total population of the world (around 65 million individuals) have vitiligo (Source: MedicineNet). In the United States, it is estimated that between 1 and 2 million people currently have vitiligo: half of whom develop it before the age of 20. While the disorder is more noticeable on people with darker skin tones, it affects all races – and both sexes – at an equal rate. It is more common in people with autoimmune diseases but the reason for the connection is still unclear. Family history may also greatly increase the chances of a child developing vitiligo, as 30% of people with the condition have a family member who also shares the same disease.
The direct causes of vitiligo are still predominantly unknown but there are several dominant theories as to what the causes might be. In the diagnosis of vitiligo, important factors include rashes, skin trauma and any sunburns around the areas of the body where the bleached signs have occurred. While some individuals have reported that a particularly bad sunburn caused their vitiligo, there is currently no evidence that sunburns can cause the condition (Source: National Institute of Arthritis and Musculoskeletal and Skin Diseases). However, many treatment options for vitiligo can greatly increase the skin’s sensitivity for sunburns; in turn increasing the risk of skin-based cancers like malignant melanoma and Merkel cell carcinoma. Depigmentation itself will bring with it some photosensitivity and broad spectrum sunscreen (that which provides protection against both UVA and UVB light) is highly recommended.
Systemic Lupus Erythematosus
Systemic lupus erythematosus (SLE) is an autoimmune disorder that will last a lifetime. It can affect the skin, joints, brain, kidneys, and other organs. This commonly causes inflammation throughout the affected areas. Nearly every SLE patient experiences swelling and joint pain and some develop additional arthritis – especially in the hands, wrists, fingers, and knees. Symptoms may also include chest pains, fatigue, hair loss, nervous system disorders, and breathing problems, along with skin rashes and photosensitivity. This condition tends to greatly alter the patient’s skin and can cause various sores and lesions.
SLE appears in people of varied ages but seems to more often affect those age 10-50 (Source: MedlinePlus). African Americans and Asians seem to also be more predisposed, while women have a higher tendency to develop SLE than men. While the underlying natural cause is unknown, another variation of the condition – drug-induced lupus erythematosus – can result from a hypersensitive reaction to certain medications and carries very similar symptoms. Diagnosis for lupus requires a physical exam in which the concerned individual must exhibit 4 out of 11 typical symptoms, in order to be sure they have lupus.
Sun exposure can be very detrimental to systemic lupus erythematosus sufferers. Even small doses of sunlight can cause scaly areas to appear on the skin that may form lesions that have a tendency to scar-over. These scarred areas have shown an increased risk of developing skin cancers such as melanoma and carcinoma. Tanning – and especially sunburns – should be strongly avoided. Most patients are advised to wear protective clothing, sunglasses and broad-spectrum sunscreen, when coming in contact with the sun, as it can cause lasting damage and a severe increase in symptoms.
Porphyrias are actually a group of disorders that are relatively rare. They result in a required portion of haemoglobin – heme – not being produced properly. While there are a number of different porphyria types, common symptoms range from muscle pain and weakness, personality changes and mental disorders to extreme photosensitivity, paralysis and hazardous respiratory problems. Symptoms can vary wildly from person to person and can also flare up instantly, during acute attacks.
While porphyrias are not considered to be autoimmune diseases, there is a very strong similarity between them. There is a chance that they will be reclassified as autoimmune diseases, at some point in time. Most patients are already evaluated for autoimmune conditions, during diagnosis and throughout their lives, when living with any type of porphyria. As a genetic deficiency, porphyrias are highly hereditary, to the point where it is highly advisable that people with any type of the condition (or a family history of it) consult with a genetic specialist, before attempting to have children. This isn’t an effective treatment for this disorder: patients instead must make a very conscious effort to avoid certain medications and lifestyle choices.
As haemoglobin creates the red pigment in red blood cells, a lack of heme tends to cause moderate to extreme sensitivity to sunlight. Some severe types of porphyria require the patient to avoid as much contact with sunlight as possible, as the skin can become visibly cracked, damaged and scarred, in a very short period of time. This also drastically increases skin cancer risk. In fact, the aversions to sunlight caused by some porphyria cases have brought some people to speculate about its relation to myths about vampires.