Psoriasis is often mistaken for a simple skin problem, but it is actually a chronic immune-mediated inflammatory disease that can affect more than just the skin. It happens when the immune system becomes overactive, causing skin cells to be produced much faster than usual. This leads to patches of inflamed, thickened, and scaly skin.
Psoriasis can affect people of any age and may come and go in cycles. A person can have periods when symptoms are mild or absent, followed by a flare-up. Although there is currently no permanent cure, several treatments can control symptoms and reduce flares.
Importantly, psoriasis is not contagious. You cannot catch it by touching someone who has it.
What Is Psoriasis?
The American Academy of Dermatology defines Psoriasis as an autoimmune condition that develops because of an abnormal immune response. Normally, skin cells are replaced gradually. In psoriasis, immune activity speeds up this process, causing new skin cells to build up on the surface much more quickly.
This produces the characteristic thick, raised patches or plaques associated with the condition. Inflammation can also cause itching, soreness, burning, and cracking.
The disease can affect different areas of the body, including the scalp, elbows, knees, trunk, palms, soles, and nails. It can also affect less visible areas such as skin folds and the genital area.
Psoriasis is considered a systemic inflammatory condition, meaning its effects can extend beyond the skin. People with psoriasis have a higher risk of certain other health conditions, including psoriatic arthritis, cardiovascular disease, metabolic disorders, and mental health problems.
What Does Psoriasis Look Like?
The appearance can vary depending on the type of psoriasis and the person's skin tone.
On lighter skin, plaques may appear pink or red with silvery-white scales. On brown or black skin, psoriasis may appear darker, purple or grey, and scaling can be more noticeable. Dark marks may remain after the inflammation settles.
Common symptoms include:
- Raised, thickened patches of skin
- Dry, flaky or scaly skin
- Itching or soreness
- Burning or irritation
- Cracked skin that may bleed
- Changes in the nails
- Scalp scaling
- Joint pain, stiffness, or swelling in some people
The severity can range from a few small patches to widespread disease affecting large areas of the body.
Different Types of Psoriasis
According to the National Psoriasis Foundation, there are several types of psoriasis.
- Plaque Psoriasis: This is the most common type. It causes raised, inflamed patches covered with scales. The elbows, knees, scalp, and trunk are commonly affected.
- Guttate Psoriasis: Guttate psoriasis causes many small, drop-shaped spots, often on the trunk and limbs. It can develop after an infection, particularly a streptococcal throat infection, and is more common in children and young adults.
- Inverse Psoriasis: This affects skin folds such as the armpits, groin, and areas beneath the breasts. Instead of thick scales, it often causes smooth, inflamed patches. Friction and sweating may make it worse.
- Pustular Psoriasis: This causes pus-filled bumps surrounded by inflamed skin. It may affect specific areas such as the hands and feet or, in severe cases, much larger areas of the body. Some forms can require urgent medical treatment.
- Erythrodermic Psoriasis: This is a rare but potentially serious form in which large areas of the skin become intensely red, inflamed, and scaly. It can affect the body's ability to regulate temperature and fluid balance and requires urgent medical assessment.
What Causes Psoriasis?
There is no single cause. Genetics and immune-system changes both appear to play important roles.
People with a family history of psoriasis are more likely to develop it, but having a relative with the condition does not mean that someone will definitely develop it.
Environmental and lifestyle factors can also influence when psoriasis appears or becomes worse. These factors may trigger the immune response or aggravate existing inflammation.
Common Psoriasis Triggers
Triggers vary between individuals. Some common ones include:
- Stress
- Skin injuries, cuts or scratches
- Certain infections
- Smoking
- Excessive alcohol consumption
- Obesity
- Some medicines
- Changes in weather or environmental conditions
A person may have one trigger or several. Keeping track of flare-ups can help identify personal patterns.
Importantly, a trigger is not necessarily the underlying cause of psoriasis. For example, stress may worsen symptoms in someone who already has the condition rather than being the sole reason they developed it.
Can Stress Cause Psoriasis?
Stress is a recognised trigger for psoriasis flares. Emotional stress can affect immune and inflammatory pathways and may make existing symptoms harder to control.
Psoriasis itself can also become a source of stress. Visible patches, itching, discomfort or concerns about appearance may affect confidence and social life. This can create a cycle in which stress worsens symptoms and symptoms increase stress.
Managing stress through regular physical activity, adequate sleep, relaxation techniques, counselling or other appropriate strategies may therefore be useful as part of overall psoriasis care.
Is Psoriasis Hereditary?
Genetics can increase the likelihood of developing psoriasis. Several genes involved in immune-system function have been associated with the condition.
However, psoriasis is not inherited in a simple way. A person can develop psoriasis without a family history, while someone with affected relatives may never develop it. Environmental factors also appear to influence whether the disease becomes active.
How Is Psoriasis Diagnosed?
There is usually no single blood test used to diagnose psoriasis.
A dermatologist generally examines the skin, scalp and nails and asks about symptoms, medical history, family history, recent illnesses, medicines and possible triggers.
If the appearance is unclear, a small skin sample may sometimes be examined under a microscope to rule out other skin conditions. Doctors may also ask about joint pain or stiffness because psoriasis can occur alongside psoriatic arthritis.
Psoriasis and Psoriatic Arthritis
According to a report published in the journal ‘Medicina’ https://www.mdpi.com/1648-9144/61/10/1809, one of the most important complications to watch for is psoriatic arthritis, an inflammatory form of arthritis associated with psoriasis.
It can cause:
- Joint pain
- Swelling
- Morning stiffness
- Pain where tendons or ligaments attach to bones
- Swelling of an entire finger or toe
- Lower back or neck stiffness
- Nail changes
Joint symptoms can sometimes occur before obvious skin symptoms. Early assessment is important because untreated inflammatory arthritis can cause permanent joint damage.
Anyone with psoriasis who develops persistent joint pain, swelling or stiffness should tell their doctor.
Psoriasis and Other Health Problems
Psoriasis can be associated with health problems beyond the skin. These include cardiovascular disease, high blood pressure, obesity, type 2 diabetes and metabolic syndrome. Anxiety and depression can also occur, particularly when psoriasis significantly affects quality of life.
This does not mean everyone with psoriasis will develop these conditions. However, regular healthcare can help identify risk factors such as high blood pressure, abnormal cholesterol, high blood sugar, and excess weight.
Treating psoriasis should therefore involve looking at the person's overall health rather than focusing only on the skin.
How Is Psoriasis Treated?
Treatment depends on the type of psoriasis, how extensive it is, which areas are affected, and how much it interferes with everyday life.
Topical Treatments
For mild psoriasis, doctors may prescribe creams, ointments, lotions or gels.
These can include:
- Topical corticosteroids
- Vitamin D analogues
- Emollients or moisturisers
- Salicylic acid
- Other prescription treatments suited to specific body areas
Topical steroids can be effective, but they should be used according to medical advice because prolonged or inappropriate use can cause skin side effects.
Phototherapy
When topical treatment is not sufficient, phototherapy, particularly controlled ultraviolet treatment, may be considered.
Narrowband UVB is one established option for psoriasis. Treatment needs to be prescribed and monitored because excessive ultraviolet exposure can damage the skin.
Oral and Injectable Medicines
Moderate to severe psoriasis may require medicines that work throughout the body.
Depending on the individual situation, doctors may consider treatments including biologic medicines. Biologics target specific parts of the immune system involved in psoriasis and may be used when appropriate for moderate to severe disease.
These medicines require medical supervision. Some can affect the immune system, liver, kidneys, blood counts, or other aspects of health, so monitoring may be necessary.
Can Diet Improve Psoriasis?
There is no single psoriasis diet that works for everyone.
A balanced diet rich in vegetables, fruit, whole grains, pulses, and other nutritious foods can support general health.
Maintaining a healthy weight is particularly important because obesity is associated with psoriasis and can also affect treatment outcomes.
There is not enough evidence to recommend restrictive diets or supplements as a replacement for established psoriasis treatment. People should be cautious about claims that a particular food, herbal product, or supplement can 'cure' psoriasis.
Does Sunlight Help Psoriasis?
Controlled exposure to ultraviolet light can improve psoriasis in some people, which is one reason phototherapy is used medically, according to a report published in BMJ Journals.
However, deliberately getting excessive sun exposure is not a safe substitute for treatment. Sunburn can itself trigger psoriasis in some people, and repeated ultraviolet exposure increases skin damage and skin cancer risk.
Anyone considering light-based treatment should discuss it with a dermatologist.
What Can You Do at Home?
Daily skin care can help reduce dryness and discomfort.
Regular use of a suitable moisturiser can help maintain the skin barrier and reduce dryness. Avoiding harsh soaps, scratching, and unnecessary skin injury may also help.
Other useful measures include:
- Following the prescribed treatment consistently
- Identifying personal triggers
- Maintaining a healthy weight
- Exercising regularly
- Avoiding smoking
- Limiting alcohol
- Getting adequate sleep
- Seeking help for persistent stress, anxiety or low mood
Stopping treatment as soon as the skin improves without discussing it with a doctor may allow symptoms to return.
Common Myths About Psoriasis
Myth: Psoriasis is contagious.
Fact: It cannot spread from one person to another through touch.
Myth: Psoriasis is only a cosmetic problem.
Fact: It is a chronic inflammatory disease that can affect physical and mental well-being and is associated with other health conditions.
Myth: Psoriasis is caused by poor hygiene.
Fact: Hygiene does not cause psoriasis.
Myth: There is one permanent cure for psoriasis.
Fact: Currently, there is no cure, but many treatments can control symptoms effectively.
Myth: Everyone with psoriasis needs strong medicines.
Fact: Not necessarily. Treatment is based on disease severity, location, type, symptoms, and individual circumstances. Mild disease may respond well to topical treatment, while more extensive disease may require phototherapy or systemic medicines.
When To See a Doctor?
Anyone with persistent scaly, inflamed, or unexplained skin patches should seek medical advice rather than self-diagnosing.
People who already have psoriasis should seek medical attention if symptoms suddenly become much worse, cover large areas of the body, or are accompanied by fever or feeling unwell.
Urgent assessment is particularly important if the skin becomes rapidly and extensively red or develops widespread pus-filled lesions, as these can indicate severe forms of psoriasis.
You should also tell your doctor about persistent joint pain, swelling or morning stiffness, as these may indicate psoriatic arthritis.
Final Word
Psoriasis is much more than dry or flaky skin. It is a long-term immune-mediated inflammatory condition that can affect the skin, nails and joints and may be associated with cardiovascular, metabolic and mental health problems. Although there is currently no cure, treatment can significantly reduce symptoms and improve quality of life. The right approach depends on the type and severity of psoriasis and should be decided with a dermatologist.
