Psoriasis is not contagious. It is an autoimmune disease with a genetic cause.



Psoriasis is a chronic autoimmune disease that mainly affects the skin. It is non-contagious. A reddish, scaly rash - often referred to as red, scaly patches - is commonly found over the surfaces of the scalp, around or in the ears, the elbows, knees, navel, genitals and buttocks.

  • The scaly patches, also known as psoriatic plaques, are areas of inflammation and excessive skin production.
  • Skin quickly builds up in the affected area, because skin production is faster than the body’s ability to shed it.
  • Areas with psoriatic plaques take on a silvery-white appearance.


Unlike eczema, psoriasis is more commonly found on the extensor aspect of a joint.


  • Psoriasis varies in severity - some patients may only have minor localized patches, while others are affected all over the body. Psoriatic nail dystrophy is common among patients with psoriasis - where the fingernails and toenails are affected. Psoriasis may also result in inflammation of the joints, as may be the case with psoriatic arthritis, which affects approximately 10% to 15% of all psoriasis patients.
  • Experts are not sure what causes psoriasis. Most believe there is a genetic component that can be triggered by a prolonged injury to the skin.
  • Excessive alcohol consumption, smoking,mental stress, and withdrawal of systemic corticosteroid medications are said to be factors that may aggravate psoriasis.
  • According to the National Health Service, UK, approximately 2% of the British population is affected by psoriasis. People with psoriasis most commonly develop symptoms between the ages of 11 and 45 years. However, it can start at any age.
  • The human body produces new skin cells at the lowest skin level. Gradually those cells move up through the layers of skin until they reach the outermost level, where they eventually die and flake off. The whole cycle - skin cell production to skin death and flaking off - takes between 21 and 28 days. In patients with psoriasis, the cycle takes only between 2 to 6 days; resulting in a rapid buildup of cells on the skin’s surface, causing red, flaky, scaly, crusty patches covered with silvery scales, which are then shed.
  • Psoriasis is a chronic condition - it is long lasting.
  • Some people have periods with no symptoms, while others live with signs and symptoms all the time. For some people psoriasis can be seriously disabling.



Although there is no current cure for psoriasis, there are treatments that can help with the symptoms.



What Are The Signs And Symptoms Of Psoriasis?

  • A symptom is something the patient feels and reports, while a sign is something other people, such as the doctor detect. For example, pain may be a symptom while a rash may be a sign.
  • In cases of psoriasis, the signs and symptoms vary from patient to patient. In the majority of cases patients find their symptoms are cyclical – with problems occurring for a few weeks or months, and then easing or disappearing for a while.
  • Even though it is possible to sometimes have two types occurring simultaneously, most patients generally have just one form of psoriasis at a time.


The signs and symptoms of the different types of psoriasis are:


Plaque psoriasis.

  • Raised, inflamed, red lesions (plaques) covered in a silvery white scale. Typically found on the elbows, scalp and knees and lower back. They can, however, appear anywhere on the surface of the body.
  • Plaques are typically itchy, sore (or both).
  • Skin around the joints may crack and bleed in severe cases.


Nail psoriasis.

  •  Yellow-red nail discoloring. It likes like a drop of oil (or blood) under the nail plate.
  • Health care professionals sometimes refer to this as an oil drop or salmon patch. Pits in the nails, also known as pitting of the nail matrix.
  • Pitting is the result of the loss of cells from the surface of the nail.
  • Lines across the nails – often referred to as Beau line by health care professionals. The lines go side-to-side, rather than from top-to-bottom.
  • The lines are caused by inflammation of the cells.


Leukonychia (midmatrix disease).

  • Areas of white on the nail plate.


Subungual hyperkeratosis.

  • The skin under the nail thickens.
  • The nail loosens – health care professionals may use the terms onycholysis of the nail bed and nail hyponychium.
  • Where the nail separates from the skin under it, a white area may develop, starting at the nail’s tip and extending downwards. The skin under the nail(nail bed) may become infected.


Nail crumbling.

  • Health care professionals may refer to nail plate crumbling at the nail bed or nail matrix.
  • As the structures that support the nail are not working properly, the nail weakens.



Splinter hemorrhage.

  • Also known as dilated tortuous capillaries in the dermal papillae.
  • These are small black lines that go from the tip of the nail to the cuticle.
  • Tiny capillaries(very small blood vessels) between the nail and the skin under it bleed, causing the lines to appear.



Spotted lunula.

  • The lunula is the crescent-shaped whitish area of the bed of a fingernail or toe.
  • It is the visible part of the nail matrix (root of the nail). The lunula becomes red when the capillaries under the nail are congested.
  • Nail changes with arthritis of the fingers – at least half of all patients with psoriatic arthritis experiences nail changes.



Onychomycosis - This is a fungal infection of the nails. Sometimes linked to nail psoriasis.



Paronychia – Inflammation of the folds of tissue around the nail, caused by an infection.

  • It may be a bacteria (staph or strep) or fungal infection. Sometimes linked to nail psoriasis.



Guttate psoriasis – Sometimes known as teardrop psoriasis or raindrop psoriasis. Plaques are usually small, no more than 1cm in diameter.

  • Plaques are fairly widespread.
  • They may develop anywhere in the body, except the soles of the feet and palms of the hands.
  • Most commonly affects the chest, arms, legs and scalp. Some signs and symptoms of nail psoriasis may also be present.
  • Usually occurs after a strep infection (throat infection) and is more common among teenagers and children.
  • There is a good likelihood that the guttate psoriasis eventually disappears completely. However, some young patients eventually develop plaque psoriasis.



Scalp psoriasis - Usually affects the back of the head. However, it can occur on the whole scalp, or other parts of the scalp.

  • Red patches of skin -  The red patches are covered in thick silvery-white scales. Can be extremely itchy (sometimes it isn’t itchy). Can cause hair loss in severe cases.



Inverse psoriasis (Flexural psoriasis).

  • More common among overweight/obese individuals. As opposed to plaque psoriasis, inverse psoriasis is not characterized by scaling.
  • Inverse psoriasis is characterized by inflamed, bright red, smooth patches of skin.
  • Can be very itchy. Can be very painful.
  • If the skin rubs together in the folds, symptoms will be aggravated. Sweating in the skin folds may also aggravate affected areas.
  • Most commonly affected areas include the armpits, groin, skin between the buttocks, and skin under the breasts.
  • In obese/overweight patients, there may be symptoms under the belly (where it folds over).



Pustular psoriasis – a much rarer type of psoriasis. There are three main types, and they affect different areas of the body:



1. Von Zumbusch psoriasis.

  • Pustules appear across a wide area of skin.
  • Pustules develop rapidly.
  • The pus is made up of white blood cells.
  • The pus is not infected. within a couple of days the pustules dry and peel off, after which the skin is shiny and smooth pustules may appear in cycles of weeks, or even a few days at the start of a cycle the patient may experience fever, chills, fatigue and weight loss.



2. Palmaplanter pustular psoriasis.

  • Pustules may appear on the soles of feet or the palms of the hands.
  • Pustules develop into round, brown, scaly sports.
  • Pustules eventually dry and peel off.
  • There may be cycles of recurrence, every few weeks or even days.



3. Acropustulosis.

  • Pustules appear on fingers and/or toes. Pustules burst. Burst pustules leave bright red areas that may become scaly, or burst pustules leave bright red areas that ooze. Sometimes symptoms of nail psoriasis appear.



Erythrodermic psoriasis – The most uncommon form of psoriasis.

  • Whole body can be covered with a fiery red rash.
  • There is usually intense itching.
  • There is typically an intense burning sensation.
  • There is widespread inflammation.
  • There is widespread exfoliation (shedding of skin), during which time itching, burning and swelling is more severe.
  • Body more susceptible to losing proteins and fluid, leading to dehydration and malnutrition (as well as heart failure).
  • Hypothermia is possible – the patient’s body temperature becomes too low; 35C (95 F) or below.



Psoriatic arthritis.

  • The majority of patients develops psoriasis first, and are diagnosed with psoriatic arthritis at a later date.
  • However, arthritis may sometimes develop before the skin lesions appear.



Joint pain.

  • Stiffness, especially first thing in the morning, or after resting.
  • Redness, swelling around the affected joints and tendons.
  • Finger(s) swells around the affected joints and tendons.
  • Reduced range of movement at the affected joint.



Symptoms of nail psoriasis.

  • Flaking silver patches of skin. Inflammation under the skin, usually red.



Iritis – inflammation of the iris.

  • The eye becomes reddened. There may be sensitivity to light.



Uveitis - inflammation involving the uvea.

  • The iris, choroid, and ciliary body (parts of the eye).
  • Symptoms may include redness of the eye, blurred vision, unusual sensitivity to light, and eye pain.
  • Inflammation of the skin and the symptoms of psoriasis



Spondylitis - inflammation of one or more of the vertebrae of the spine.

  • Inflammation can also occur where ligaments and tendons attach to your spine.
  • Symptoms may include pain and stiffness in the lower back, upper buttock area, neck, and the rest of the spine.
  • Symptoms are usually worse on waking up, or after long periods of inactivity.



What Are The Risk Factors For Psoriasis?

  • A risk factor is something which increases the likelihood of developing a condition or disease. For example, obesity significantly raises the risk of developing diabetes type 2. Therefore, obesity is a risk factor for diabetes type 2.




The following factors may increase a person’s risk of developing psoriasis:

  • Family history - if an individual has a close relative who has/had psoriasis, their risk of developing the condition is significantly higher, compared to other people.
  • Approximately 30% of all patients with psoriasis have a close relative who also has the condition.
  • There are 3 genes that are associated with psoriasis - SLC9A3R1, NAT9 and RAPTOR genes.
  • Having those genes does not necessarily mean an individual will develop psoriasis - many people with those genes never develop any skin conditions.
  • HIV - patients with HIV have a higher risk of developing psoriasis, compared to people who don’t have HIV.
  • Recurring infections - people with recurring infections, particularly strep throat (streptococcal throat infections), have a higher risk of developing psoriasis.
  • This is especially the case with children and young adults. Even so, the chances of developing psoriasis as a result of a throat infection for most people are very small.
  • Mental stress - high stress levels may increase an individual’s risk of developing psoriasis, because stress has an effect on the immune system.
  • Overweight or obesity - people who are overweight or obese have a higher risk of developing inverse psoriasis.
  • Plaques linked to most types of psoriasis are more likely to develop in the skin folds and creases.
  • Regular tobacco smoking - not only is the risk of developing psoriasis higher, but also its severity.
  • Experts believe smoking may be a factor in the initial development of the condition.



What Are The Causes Of Psoriasis?

Experts are not sure what the exact cause of psoriasis is. We know the immune system plays a part, and we also know there is excessive growth and reproduction of skin cells.



Fault of the epidermis.

  • One hypothesis is that psoriasis is mainly a fault of the epidermis (the upper or outer layer of skin) and its keratinocytes.
  • The keratinocyte is the major constituent of the epidermis, making up 95% of the cells found there.
  • Keratinocytes are cells found in the epidermis - those at the outer surface of the epidermis are dead and form a tough protective layer, while the cells below divide and replenish the supply.



An immune-mediated disorder.

  • Another hypothesis is that the excessive reproduction of skin cells is secondary, and that the main factor is related to an immune system disorder.
  • Our immune system is designed to protect us from foreign bodies and pathogens (things that cause disease), such as bacteria, viruses, and toxic substances.
  •  An autoimmune reaction occurs when the immune system mistakes a normal or good substance for a pathogen, and attacks it. Sometimes our immune system may attack good tissues and cells in our bodies; this is called an autoimmune disease.
  • Our T-cells (T lymphocytes) normally help protect the body against infection - they are a type of white blood cell and form part of our immune system.
  • T cells travel throughout the human body to detect and fight off foreign substances, such as bacteria or viruses. If a person has psoriasis, however, the T cells attack healthy skin cells by mistake.
  • Experts believe these T-cells become active, migrate to the dermis (inner/deeper layer of skin) and trigger the release of cytokines, in particular tumor necrosis factor-alpha (TNFα).
  • TNFα is what causes the excessive production of skin cells, as well as inflammation.
  • Experts do not know what triggers the activation of T-cells - genetic and environmental factors are most likely, they say.
  • The result is a cycle of skin cell production becoming faster and faster.
  • It normally takes 28 days for skin cells to be created and then to die - this cycle is reduced to 2 to 6 days in patients with psoriasis, causing dead skin cells to accumulate on the surface of the skin, in thick scaly patches.



Psoriasis Triggers.

  • A trigger is anything that either: Sets off a disease in people who are predisposed to developing it, or Causes certain symptoms to occur (or get much worse) in a person who already has a disease/condition.
  • People, who already have psoriasis, may find that these triggers make symptoms start or become worse:
  • Alcohol consumption (especially heavy alcohol consumption).
  • Infections - in some cases infections can trigger psoriasis. Dermatologists say that patients with a family history of the condition get strep throat and develop their first psoriasis lesions within a couple of weeks, especially guttate psoriasis. Candida albicans - a thrush infection may aggravate inverse psoriasis symptoms.



The following infections may also trigger psoriasis:

  • HIV (human immunodeficiency virus).
  • Boils (staphylococcal skin infections).
  • Viral upper respiratory conditions. If the infection is treated, symptoms often lessen or clear completely.
  • Smoking.
  • A skin cut, scrape, sunburn, or insect bite.
  • Mental stress.
  • Cold weather.
  • Some medications - some patients already with psoriasis may experience a flare-up. while others may have psoriasis for the first time after taking certain types of medications: Anti-malarial drugs - experts say people may develop symptoms for the first time after taking these medications.
  • Beta-blockers - used for treating angina, high blood pressure (hypertension), some abnormal heart rhythms, heart failure, myocardial infarction (heart attack), anxiety, overactive thyroid symptoms, glaucoma and migraine.
  • Symptoms worsen for somepatients with psoriasis.
  • Corticosteroids - these medications can be very effective in the treatment of psoriasis symptoms. However, overuse and sudden withdrawal may in some cases aggravate symptoms.
  • Some non-steroidal medications used for treating arthritis and other inflammatory conditions - such as Indomethacin, may aggravate symptoms.
  • Lithium - used in the treatment of bipolar disorder and some other psychiatric conditions, may aggravate symptoms in a significant number of psoriasis patients.
  • Ace-inhibitors - used for the treatment of hypertension (high blood pressure). May aggravate symptoms in psoriasis patients.



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