man applying topical medication cream onto his elbow for psoriasis treatment

Psoriasis 101: Overview, Symptoms, Causes & Treatment

Learn all you need to know about psoriasis, including its symptoms, causes, triggers, types and the treatment options available.

by Elaine Francis, R.N.

Affecting around 1% of the population of Singapore, psoriasis is a fairly common autoimmune condition that affects the skin.

What is Psoriasis?

Psoriasis is a chronic skin condition where the skin cells multiply much faster than normal, resulting in itchy red patches of skin. These patches often have silvery scales, especially when the surface is scratched, and can become slightly raised and rough as the skin thickens. Sometimes, these patches may crack and bleed. 

Psoriasis tends to happen in cycles. Symptoms may flare up for a few weeks or months, then subside or go into remission.

An autoimmune condition, psoriasis causes the body’s own immune system to attack healthy cells, resulting in inflammation and other problems. It is sometimes linked to other autoimmune conditions too.

Women and men are equally affected by psoriasis. It can be diagnosed at any age but is often discovered earlier in life, with most people developing the condition sometime between their teens and their early thirties.

There are several different forms of psoriasis which affect the skin and nails. Psoriasis can also present as a form of arthritispsoriatic arthritis. 

The severity of psoriasis can vary a lot from one person to the next, and different people respond to different treatments in different ways, so it’s important to have support from a medical team who are experienced at managing skin conditions like psoriasis.

Psoriasis tends to happen in cycles. Symptoms may flare up for a few weeks or months, then subside or go into remission.

Types of Psoriasis

There are several types of psoriasis which can appear vastly different from one another. It is possible to have two or more forms of psoriasis at the same time, and it is also possible to have psoriasis alongside other skin conditions.

Plaque Psoriasis

Plaque psoriasis is the most common form and is usually found on the outside bends of the elbows and the knees, although it can be spread to other places too. It typically causes areas of red, thickened skin. When scratched, the skin flakes off in small silvery scales.

Guttate Psoriasis

Guttate psoriasis often occurs after a viral infection, such as strep throat. The word ‘guttate’ comes from the same Latin word root as ‘gutter’, because it appears as lots of small psoriasis plaques scattered like raindrops over the body.

Scalp Psoriasis

Psoriasis on the scalp is relatively common. Scalp psoriasis appears as itchy, flaky areas on the head, sometimes extending down the neck and onto the face and ears. It can be harder to apply topical medications to the affected areas under hair, but medicated shampoos and lotions are available. The flakes of psoriasis in the hair can look somewhat like dandruff. 

Pustular Psoriasis

Pustular psoriasis is a form of psoriasis with lots of tiny white pustules – like tiny blisters filled with white fluid. People who get pustular psoriasis usually see it most on the hands and feet – known as palmoplantar pustular psoriasis. The fluid in the pustules is not infectious and is not the result of an infection.

A rare condition called generalised pustular psoriasis causes these tiny white pustules to appear on top of itchy red patches all over the body. They are usually accompanied by general flu-like illness. Generalised pustular psoriasis requires urgent medical attention.

Nail Psoriasis

Psoriasis of the nailbeds often accompanies other forms of psoriasis. The nails become pitted, with lots of tiny dents all over, and sometimes discoloured patches with an ‘oil spot’ appears. It can affect some or all of the nails. More severe nail psoriasis can cause thick, powdery skin to develop under the nail, which can cause the nail to lift.

What is Psoriatic Arthritis?

Around 1 in 4 people with psoriasis develop psoriatic arthritis, also known as psoriatic arthropathy. This is a form of arthritis which has a similar cause to psoriasis – an autoimmune condition which affects healthy cells, causing inflammation and overproduction of cells.

Is Psoriasis Contagious?

Psoriasis is not contagious. It is an autoimmune condition, which means that it is a result of the immune system causing damage to the body’s own cells. There is a genetic element, meaning that it often runs in families. People who have a close relative with psoriasis are more likely to have the disease, but it is not always predictable and may appear to ‘skip’ generations.

As psoriasis is visible, it is a condition which can attract unwanted attention. Some people may find it uncomfortable showing skin which appears red and scaly and may be put off wearing clothing which exposes the rash or visiting swimming pools.

Psoriasis Symptoms

The symptoms of psoriasis vary by type, but the most common symptom is red, itchy areas on the skin. Psoriasis can appear on any part of the body and may be particularly uncomfortable and problematic in sensitive areas like the genitals. 

Plaque psoriasis, in particular, tends to affect the outer areas of the elbows and knees and is characterised by thickened red, itchy and scaly skin. Some people have flaky psoriasis on their scalp, and people with nail psoriasis typically have pitting on the surface of the nails, sometimes accompanied by some thickening and lifting of the nail from the nail bed. People who develop psoriatic arthritis describe general arthritis symptoms, which includes painful, swollen joints with restricted movement. Commonly affected joints include the hands, feet, knees, lower back and neck.

Psoriasis Causes

Psoriasis is an autoimmune condition; a condition where the immune system attacks the body’s own cells as if they were intrusive and damaging organisms like bacteria or viruses. As the body attacks healthy skin cells, there is an inflammatory response and the body begins to make more skin cells. This means that people with psoriasis produce skin cells at a much quicker rate than normal. 

Normally, skin cells have a lifespan of around three weeks – they are naturally replaced, and old cells slough off. In psoriasis, the skin cells are replaced every few days, resulting in a build-up of both living and dead cells. This build-up appears as psoriasis – thickened plaques and flaky skin.

The exact cause of psoriasis is not fully understood; the reason that some people develop autoimmune diseases and others do not is complex and likely due to a combination of genetic and environmental factors. The body’s inflammatory response is also complex and varies from person to person. Treatments for psoriasis work by reducing the overproduction of skin cells, by modifying the inflammatory response, or by reducing the autoimmune response of the immune system.

Psoriasis Triggers

Certain triggers can cause the symptoms of psoriasis to flare up. 8 common triggers include:

1. Friction 

Wearing uncomfortable and abrasive fabrics can cause a psoriasis flare-up. Anything which abrades away at psoriasis plaques can shear off the top and expose raw skin underneath, as well as irritate healthy skin and trigger flares.

2. Sunburn

A little sunshine is known to help psoriasis; in fact, UV light is used as a treatment for psoriasis. However, exposure to strong sunlight over a long period causes sunburn, which can trigger a flare-up and increase the risk of skin cancer. This is different from UV light therapy, where UV light is carefully administered and closely monitored to prevent complications.

3. Weather

Although a little sunlight can improve psoriasis, hot weather and sweat can make it worse. On the flip side, colder weather means there’s less sunlight and greater exposure to artificial heating and dry air, which also worsens psoriasis.

4. Smoking

There is a direct link between smoking and psoriasis; and it seems that the more someone smokes, the worse their psoriasis becomes.

5. Alcohol

Alcohol can trigger flare-ups and may also interact with some of the medications used to treat more severe psoriasis.

6. Stress

Many people with psoriasis find that the condition worsens when they are stressed, and a flare-up can, in turn, make a person feel more stressed and uncomfortable. Hence, having stress-mediated psoriasis can feel like being in a loop of worsening symptoms.

7. Hormonal Fluctuations

Changes in hormone levels, particularly the female hormones which regulate periods, can affect psoriasis. It is not uncommon for psoriasis to first appear around the time of a girl’s first period, and follow a fluctuating pattern in line with those hormonal changes.

8. Illness

Many illnesses, particularly viral infections, seem to trigger psoriasis, and are often the first thing to trigger the first instance of the condition. Strep throat – a throat infection caused by the streptococcus virus – is particularly known for triggering guttate psoriasis.

Some people find that certain foods trigger their psoriasis but there isn’t much research that confirms this. However, keeping a diary to help track of the relationship between flare-ups and potential triggers can help people plan the best course of management for their psoriasis.

There is also a strong link between obesity and psoriasis – weight loss and maintaining a healthy weight can often improve symptoms.

Is There a Cure for Psoriasis?

Presently, there is no cure for psoriasis. However, there are many treatment options available that can help to manage the symptoms or possibly make it go into remission.

As it is a genetic autoimmune disease, if someone has psoriasis they will always have it; or at least have the tendency or potential for it to come back. Most people with psoriasis find that it comes and goes to some degree – periods where it is at its worst are called flare-ups, and periods where it is mild may be referred to as remission. Some people find that they usually only have mild symptoms and may go long periods between flare-ups. Others have severe psoriasis with frequent flare-ups which are difficult to control.

Medical research is always ongoing, and treatments for psoriasis are improving all the time. Managing autoimmune conditions can be complex but is an area of cutting-edge research and medical development.

Psoriasis Treatment

There are a number of different treatment options for people with psoriasis, and treatment will be chosen based on a number of factors, such as the severity of the condition, its response to treatment, and how well an individual is able to follow a treatment regime.

1. Simple Topical Treatment

Between flare-ups, following a careful skincare routine can help the skin stay healthy. Using greasy emollients such as bath additives and soap substitutes and avoiding perfumed products or drying soaps can maintain good skin condition.

2. Topical Medications

Medicated creams or ointments applied to the skin are usually the first line of treatment for psoriasis. Ointments which contain the vitamin D analogue calcipotriol modify the skin’s tendency to overproduce cells and help control psoriasis plaques. Preparations containing coal tar have also been used with good results for many years, though the smell and tendency to stain clothes and bedding can be off-putting for some. Dithranol is another medication which is applied to the skin to reduce the overproduction of skin cells.

3. Topical Corticosteroids

Mild steroid creams or ointments such as hydrocortisone or stronger forms such as Betnovate (betamethasone valerate) can be an essential part of treatment during a flare-up, but should not be overused as they can cause the skin to thin. They should be applied carefully only to the affected area. Some people find that psoriasis flares back up if they suddenly stop using the steroid creams, so weaning off them gradually is recommended.

4. Phototherapy

Also known as UV light therapy, phototherapy is usually used when psoriasis doesn’t respond well to topical treatments. The skin is exposed to UV rays which slow down the production of skin cells. There are two types of rays used in phototherapy: UVA and UVB. UVB is usually tried first, as it has lower risk of complications than UVA. UVA is usually used alongside a medication called psoralen, which makes the skin more sensitive to light rays. Psoralen plus UVA treatment may be referred to as PUVA.

If someone is having light therapy, they usually need to attend hospital several times a week for several weeks, so it can be troublesome for people who do not live near a treatment centre or are less mobile. However, medical escort and non-emergency ambulance services can be arranged. It is also important to note that while UV light therapy is carefully administered and monitored, it may still slightly increase a person’s risk of developing skin cancer.

5. Immunosuppressant Drugs

Drugs which work to partially suppress the immune response (such as methotrexate) are systemic treatments – this means that it has an effect throughout the whole body. Immunosuppressant drugs used to help with psoriasis reduce the body’s inflammatory response. Although many people have no problems with immunosuppressants, they need to be carefully monitored as they can cause side effects ranging from mild to severe. 

6. Biologics

Another systemic treatment (one which affects the whole body), biologic agents are often used as a last resort for severe psoriasis that has not responded to any other treatment. They are usually given as injections and need to be monitored carefully. They can be effective but side effects are fairly common. Biologics used for psoriasis include etanercept, infliximab, and adalimumab.

Depending on the area affected, different types of treatment may be recommended. Some of the strong topical treatments used directly onto the thick plaques of the knees and elbows would not be suitable for the face or more delicate and sensitive areas like the genitals.

For a treatment to be effective, it has to be practical and practicable; if a person is unable to follow a treatment routine where they have to apply creams to their entire body several times a day, then a different treatment should be considered. Similarly if a person is unable to attend a clinic for UV therapy, then the treatment is not the best solution for that individual. Some medical treatments may cause side effects in some people, and finding the right treatment for an individual is not always as simple as finding the right treatment for their skin alone.

When to See a Doctor about Psoriasis

Skin conditions can sometimes look similar to one another, and the types of treatment each of them require can vary vastly. This means that it is important to see a doctor and get a definite diagnosis for problems. Some skin conditions can be managed at home with simple moisturisers and emollients, but most of the treatments for psoriasis – even the lowest level of treatments – are specialist medications which need to be prescribed properly.

Usually, psoriasis is diagnosed based on the appearance of the skin and other symptoms, but occasionally a doctor might request further investigations. One of the investigations that may be requested if a diagnosis isn’t clear is a skin biopsy. This involves taking a very small sample of skin from an affected area for inspection under a microscope. They may also take a sample of unaffected skin to compare. Mild psoriasis can usually be managed by general practitioners in the community, but if the condition does not respond to treatment or is particularly severe and debilitating, a referral to a skin specialist (dermatologist) may be necessary.

Any skin condition with the following characteristics should warrant an examination by a doctor:

  • Does not clear up with simple treatments
  • Extremely painful
  • Causing distress from pain, itching, or its appearance
  • Associated with other symptoms like joint pain or fever

Psoriasis and Other Conditions

Psoriasis on the skin can be painful and flare-ups need careful management. The discomfort and severe itch of psoriasis can have a significant effect on a person’s general health and well-being – with sleepless nights, intensive treatments and constant pain. One of the symptoms of psoriasis that isn’t always as easy to address is the tiredness that can accompany a flare-up. A skin condition can affect the way you feel, inside and out, and it’s important to be aware of the effects it can have.

Mild psoriasis is not dangerous and does not appear to have any effect on a person’s lifespan, though painful, itchy flare-ups can affect a person’s quality of life. Some people find the appearance of the rash unsightly and embarrassing. If you find that having psoriasis is affecting your life and the way you feel about yourself, it’s important to see a doctor to help get the condition under control and find ways to manage it. As flare-ups aren’t always predictable, living with psoriasis may mean that you will have to accept that your skin will sometimes be visibly red and sore.

People with more severe psoriasis may be more likely to develop certain other conditions. Around a quarter of people with one autoimmune disease will go on to develop at least one more, and people with severe psoriasis are more likely to develop conditions like thyroid dysfunction or coeliac disease. That still means that three-quarters of people with psoriasis will not be diagnosed with another autoimmune condition – it’s just important to be aware of possible links and risk factors when other symptoms are being investigated.

Living with Psoriasis

Psoriasis is highly visible and some people can have negative ideas about skin conditions. Managing the way you feel about yourself when your skin looks inflamed and flaky can be difficult, and comments or glances from other people can make It even harder. In addition, any negative feelings about yourself can be made worse by the discomfort and sleeplessness that accompanies a flare-up. After all, fatigue makes everything feel harder to cope with.

It’s important to remember that you are not alone. Many people around the world have psoriasis and other visible health conditions. Flare-ups come and go, and finding support can help. 

Support can take the form of friends or family and external support networks, both formal and informal.  Some online communities have driven a trend for understanding and even celebrating visible differences, and body positivity is an important movement in promoting acceptance of things that have sometimes been viewed as flaws. Consider joining the support networks available for people with psoriasis, from social media groups to international organisations offering support, funding research, and raising awareness and understanding of the condition.

Medical input to help manage the condition can be helpful as well. However, having to visit a doctor each time you have a flare-up can be a hassle, especially if it happens frequently. Furthermore, you may not feel like leaving home due to the discomfort and the appearance of your skin. Thankfully, you can get a teleconsultation with a doctor online in as quickly as 30 minutes. Through a video call, a licensed doctor can assess your condition, develop a treatment plan and prescribe medication for your condition. If you would feel more at ease consulting with a doctor face-to-face, house call doctors are available as well. This way, you can get timely medical attention without stepping out of your home.

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  3. Healthline (2019) Is Psoriasis an Autoimmune Disease?
  4. Naldi L. (2016). Psoriasis and smoking: links and risks. Psoriasis (Auckland, N.Z.), 6, 65–71.
  5. Svanström, C., Lonne-Rahm, S. B., & Nordlind, K. (2019). Psoriasis and alcohol. Psoriasis (Auckland, N.Z.), 9, 75–79.
  6. Kunz, M., Simon, J. C., & Saalbach, A. (2019). Psoriasis: Obesity and Fatty Acids. Frontiers in immunology, 10, 1807.
  7. Psoriasis: More than skin deep. Harvard Health. (2010). Retrieved 17 February 2021, from
  8. Cojocaru, M., Cojocaru, I. M., & Silosi, I. (2010). Multiple autoimmune syndrome. Maedica, 5(2), 132–134.

About the Writer
Elaine Francis, R.N.
Elaine Francis is a registered nurse with 17 years’ experience in healthcare. She turned to writing to follow her passion for realistic medical communication. She loves translating medical jargon into accessible language for the people who need to understand it most. When she’s not writing or working on a busy cardiology unit, she spends her time telling her children to hurry up.
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