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Psoriasis is an autoimmune skin condition which is sometimes associated with arthritis. Symptoms is psoriasis range from a mild rash to severe debilitating pain.
Psoriasis is an autoimmune inflammatory skin disorder first described by Ferdinand von Hebra in 1841. In psoriasis skin cells replicate at a faster rate than usual, with new skin cells produced about eight times faster than normal. This causes skin cells to build up on the skin's surface, forming patches of scaling flakes. About 10 to 30 percent of people with psoriasis can also develop a related condition of arthritis known as psoriatic arthritis. Psoriasis ranges from a mild rash or itching affecting a small area of the skin surface to a condition causing widespread itching, pain, and pustules affecting nearly all areas of the body. There are five basic types of psoriasis, with plaque psoriasis being the most common type. About 80 percent of people with psoriasis have plaque psoriasis, which is characterized by patches of raised, reddish skin covered by a silvery-white scale. Lesions in plaque psoriasis can occur anywhere on the body although they are most commonly found on the elbows, knees, umbilicus, lower back, and scalp. Plaque psoriasis may initially manifest as gutttate psoriasis, and all forms of psoriasis may eventually progress to erythrodermic psoriasis affecting the entire body surface. The other types of psoriasis include guttate psoriasis, which causes small, red spots on the skin; pustular psoriasis, which causes white pustules surrounded by red skin, which may merge to form large areas of pus, and its variant psoriasis vulgaris, which causes small sterile pustules; inverse psoriasis, which causes smooth red lesions in the folds of the skin; and erythrodermic psoriasis, which causes widespread redness, severe itching, and pain. All types of psoriasis generally cause lifelong conditions with periods of remission alternating with periods in which there are flares. Psoriatic diaper rash appears to be the most common type of psoriasis in children under the age of two years. Localized forms of psoriasis include acrodermatitis continua suppurativa or Hallopeau's disease. Besides the skin, the fingernails, toenails, and the soft tissues of the genitals and inside of the mouth may be affected in psoriasis. Who is Affected? Men and women are affected equally by psoriasis. Approximately 150,000 new cases of psoriasis are reported each year, with about 20 percent of patients having severe cases. In the United States, more than 4.5 million adults have been diagnosed with psoriasis. Caucasians are affected more often than African Americans, and worldwide, psoriasis is most common in Scandinavia and other parts of northern Europe. Psoriasis is less likely to occur in Asians, and it is rare in Native Americans. Similar to other autoimmune diseases, psoriasis is more likely to occur in people who have another autoimmune condition, especially diabetes or Crohn's disease. People with a family history of psoriasis are also more likely to develop psoriasis. Signs and symptoms of psoriasis usually show up in people between 15 and 35 years of age, and more than 75 percent of cases first show up in people younger than 40. Although psoriasis can occur in people of any age group, new cases that occur in people older than 40 tend to target the 50-60 year old age group. Psoriatic diaper rash appears to be the most common type of psoriasis in children under the age of two years. Similar to other autoimmune diseases, psoriasis is more likely to occur in people who have another autoimmune condition, especially diabetes or Crohn's disease. People with a family history of psoriasis are also more likely to develop psoriasis. In children, symptoms of psoriasis show up earlier in girls than boys. Triggers Like other autoimmune diseases, psoriasis is caused by a combination of genetic and environmental factors. Specific immune system genes or HLA markers cause a genetic predisposition. These people who are genetically predisposed develop psoriasis when they're exposed to certain environmental triggers. These triggers include stress, skin injuries and trauma, infection with streptococcus bacteria, viral infections including infection with the human immunodeficiency virus (HIV), certain medications, particularly anti-malarial drugs, beta blockers, and lithium, and sunburn. A photosensitive form of psoriasis has been reported with psoriasis developing in sun-exposed skin in a paitent with vitliligo. Tissue changes Symptoms of psoriasis usually improve in the summer and worsen in the winter months. Compared to normal skin, the skin in psoriasis shows a thickening of the outer cell layers and also the inner cornified layer. Inflammatory changes include infiltration with white blood cells and an increased number of dermal blood vessels. Treatment Treatment consists of immunosuppressive agents such as methotrexate, vitamin D3 analogues, systemic retinoids, laser therapy, and psoralen/ultraviolet A phototherapy. Newer biologics have recently been approved as treatments for psoriasis, including alefacept, efalizumab, and etanercept. Other compounds under investigation include monoclonal antibodies, cytokines, and fusion proteins. The National Institutes of Health has comprehensive treatment information available in an online treatment booklet. Complications Recent studies show that patients with psoriasis have an increased risk of heart disease. This is particularly evident in younger patients. Read my blog for more information on increased risk of heart disease in psoriasis. Resources: Psoriasis.net, http://www.skincarephysicians.com/psoriasisnet/whatis.html Michael Schon and Wl Henning Boehcke, Psoriasis, The New England Journal of Medicine, may 5, 2005, vol 352: 1899-1912. Torchia D, Terranova M, and Fabbri P, Photosensitive psoriasis in a vitilgo patient, Journal of Dermatology, December 2006l 33(12):880-883.
The copyright of the article Psoriasis in Autoimmune Disease is owned by Elaine Moore. Permission to republish Psoriasis in print or online must be granted by the author in writing.
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