Psoriasis: Causes, Symptoms and Treatment

Published: 30.03.2026 | Updated: 02.10.2026 | Reading time approx. 14 min.

Psoriasis affects around 2–3% of the population – more than 125 million people worldwide live with red, scaly patches of skin. It can take a real toll on quality of life and increases the risk of depression.

Psoriasis is not contagious: you can’t catch it through touch, a shared swimming pool or a handshake. There is no permanent cure, but the condition can be kept under control and its symptoms eased. In this article, you’ll find reliable information on what causes psoriasis, how to recognise its symptoms and how it is treated – as well as what really matters in your everyday skincare.

Have a question about your own skin? Scroll to the end of this article – I’m happy to advise you by email.

What is psoriasis?

How psoriasis develops, step by step

Psoriasis is a chronic inflammatory skin condition that affects the whole body. It is immune-mediated, with an autoimmune component: the immune system – more specifically, T cells – mistakenly targets healthy skin cells, triggering inflammation and abnormally speeding up their renewal. In healthy skin, keratinocytes take 28–30 days to mature. In psoriasis, the same process takes just 3–7 days.

The result is visible to the naked eye: immature cells build up on the skin’s surface, forming the characteristic thick, silvery scales and psoriatic plaques on a red-brown, inflamed base.

Psoriasis vs eczema and other skin conditions: how to tell them apart

Psoriasis is surprisingly easy to confuse with seborrhoeic dermatitis, eczema or a fungal skin infection – especially when the patches are mild or appear on the scalp. That’s why a diagnosis should always be made by a dermatologist, based on a clinical examination.

Psoriasis vs eczema – key differences

Psoriasis and eczema (atopic dermatitis) can look alike at first glance: both cause red, dry, itchy patches and both tend to come and go in flare-ups. A closer look, however, reveals several clear differences.

	Psoriasis	Eczema (atopic dermatitis)
Typical areas	Outer elbows, knees, scalp, lower back	Inner elbows, backs of the knees, neck, wrists, ankles
Appearance	Thick, raised, sharply defined plaques with silvery scale	Less defined, dry patches; may weep or crust, and thicken with scratching
Itch	Can itch, but also sting or burn	Usually intensely itchy
Typical onset	Most often in teenagers and adults	Most often in babies and young children
Common triggers	Throat infections, skin injury, stress, alcohol, smoking, certain medicines	Irritants (soaps, detergents), allergens, heat and sweat, stress
What’s behind it	Immune-mediated inflammation that speeds up skin renewal	Weakened skin barrier combined with an overactive immune response

Seborrhoeic dermatitis is another condition often mistaken for psoriasis. It is a chronic condition linked to overactive sebaceous glands and the presence of Malassezia yeasts on the skin. It mainly affects the folds beside the nose, the eyebrows, the area behind the ears and the scalp, where it appears as red, flaky, greasy patches (British Association of Dermatologists).

In less clear-cut cases, two characteristic signs can help. The candle wax sign: when a scale is scraped off, the surface beneath looks shiny, as if coated in wax. The Auspitz sign: tiny pinpoint spots of bleeding then appear underneath. If the picture is still unclear, a doctor may take a skin biopsy for histopathological examination.

What causes psoriasis?

Is psoriasis genetic?

Genes play an important – though not straightforward – role in psoriasis. Inheritance is polygenic, meaning many genes are involved, and the best-studied marker is a variant of the HLA-Cw6 gene. The risk of developing psoriasis is 1–2% when neither parent has it, rises to 10–20% when one parent does, and reaches 50–70% when both do. A genetic predisposition alone, however, doesn’t mean psoriasis will develop. Genes prepare the ground, but the condition needs an additional trigger to appear – without one, those genes may stay ‘dormant’ for life.

Psoriasis triggers: what sets off or worsens a flare-up

Among the most common triggers are bacterial infections, especially those caused by streptococci and staphylococci. Strep throat is one of the best-documented triggers of a first episode, particularly of guttate psoriasis. Certain medicines can also bring on psoriasis or make it worse, including beta-blockers, lithium, NSAIDs (non-steroidal anti-inflammatory drugs) and antimalarials. Stopping oral or injected corticosteroids suddenly can also cause a flare-up.

Lifestyle matters too: chronic stress, smoking, heavy drinking, obesity and using unsuitable skincare products can all play a part. So can the weather – cold, dry air dehydrates the skin and weakens its barrier, which is why many people notice their psoriasis gets worse in winter. Hormonal changes, such as pregnancy, may also affect symptoms, for better or for worse.

It’s also worth knowing about the Koebner phenomenon: during an active phase of the disease, new psoriasis patches can appear at sites of skin injury – even minor scratches – within 6–12 days.

Is psoriasis contagious?

No. Psoriasis is driven by the immune system, which mistakenly reacts against the body’s own skin cells. It has nothing to do with cleanliness or hygiene habits. You can’t catch psoriasis through touch, a handshake, a shared swimming pool or being in the same room as someone who has it. Public awareness of this matters: it has a direct impact on the everyday comfort of people living with psoriasis.

Psoriasis symptoms

Early signs of psoriasis

The first signs of psoriasis are often subtle and easy to dismiss or mistake for another skin problem. Small reddish bumps or spots may appear, along with mild flaking in places that never caused trouble before, dryness and itching. Over time, the patches can grow, thicken and become covered in the characteristic silvery scale.

What psoriasis looks like also depends on your skin tone. On fair skin, the patches are usually pink or red with silvery-white scale. On brown or black skin, they may look purple, greyish or dark brown, and redness can be much harder to see. Once the patches have cleared, they may leave temporary lighter or darker marks.

The areas where psoriasis most often appears – the so-called predilection sites – are the elbows, knees, scalp and lower back. If the patches appear in exactly these places, it is an important diagnostic clue.

Types of psoriasis and their symptoms

Type	What it looks like
Plaque psoriasis (psoriasis vulgaris)	The most common type, affecting 80–90% of people with psoriasis. Oval, raised plaques covered in silvery scale, clearly separated from healthy skin
Scalp psoriasis	Thick, dry, firmly attached scale on the scalp, often extending beyond the hairline onto the forehead, neck or behind the ears. Can be very itchy and is often mistaken for dandruff
Pustular psoriasis	Red, swollen skin covered in pus-filled spots. The generalised form is one of the most severe
Psoriatic arthritis (PsA)	Pain, swelling and stiffness in the joints. Affects around 10–30% of people with psoriasis and, if left untreated, can lead to permanent joint damage
Guttate psoriasis	Small, drop-shaped spots on the trunk, arms and legs. Appears suddenly, often after a throat infection. Typical in children and young adults
Inverse (flexural) psoriasis	Patches in skin folds – the groin, armpits and under the breasts. Bright red and shiny, without the typical scale
Nail psoriasis	Pitting (tiny dents in the nail surface), yellowish discolouration and onycholysis – the nail lifting away from the nail bed. Affects around 50% of people with psoriasis
Erythrodermic psoriasis	The most severe form – inflammation covers almost the entire body. It comes with fever, intense itching and a racing heartbeat, and requires hospital treatment

Living with psoriasis: quality of life and related conditions

Psoriasis affects every part of daily life. Many people withdraw socially, avoid swimming pools, beaches and sport, and keep their skin covered. Research shows that psoriasis can reduce quality of life to a degree comparable with heart disease or cancer.

Chronic inflammation and the stress of living with the condition increase the risk of depression, anxiety and addiction. Heavy drinking and smoking – which some people turn to as a way of coping – make psoriasis worse. Psoriasis is also a systemic disease: widespread inflammation raises the risk of diabetes, high blood pressure, atherosclerosis and heart attack. It is also linked to a higher risk of inflammatory bowel disease, such as Crohn’s disease, and of inflammatory eye conditions such as uveitis. This is one more reason not to dismiss the symptoms and to start treatment as early as possible.

Psoriasis in children

Can children get psoriasis?

Psoriasis can develop at any age, including in children and teenagers. So-called type I psoriasis vulgaris is strongly linked to genetic predisposition and appears before the age of 40 – often in childhood or adolescence. Guttate psoriasis is particularly common in children: it appears suddenly, usually after a streptococcal infection such as strep throat.

Type I tends to be more severe and harder to treat than type II, which develops in adults after the age of 40. Early diagnosis really matters here – the sooner the right approach is in place, the better the chance of keeping the condition under control and reducing the risk of complications.

Treatment and skincare for children with psoriasis

Treating psoriasis in children calls for an individual approach, with methods chosen to suit the child’s age, how severe the symptoms are and where the patches appear. In everyday care, emollients and gentle cleansers free from harsh detergents and fragrance play a special role. Used regularly, they help rebuild the skin’s hydrolipid barrier, ease itching and may reduce the risk of flare-ups.

The emotional side matters just as much. For a child, psoriasis is not just a skin problem – it can affect friendships, self-esteem and life at school. Psychological support for the child is an important part of care.

Psoriasis treatment

Can psoriasis be cured?

Psoriasis can’t be cured for good, and flare-ups are the rule rather than the exception. It’s worth accepting this without discouragement: it doesn’t mean helplessness, but rather the need for long-term, informed management of the condition. The aim of treatment is to ease symptoms, achieve remission, keep it going for as long as possible and prevent complications that could lead to more severe forms of the disease.

Every case of psoriasis needs an individual approach, with treatment matched to how severe and widespread the patches are, where they appear and how often flare-ups return. Treatment can be topical (applied to the skin), systemic (working throughout the body) or a combination of both.

Topical treatments

Topical treatment is used when psoriasis covers up to around 10% of the body’s surface. The priority is to remove the scale and slow down the excessive growth of skin cells. The options include:

• Keratolytics – salicylic acid (5–10%) or urea. They reduce scaling and help other active ingredients penetrate the skin.
• Topical corticosteroids – strongly anti-inflammatory and immunomodulating. They should only be used under medical supervision, as incorrect use carries a risk of side effects.
• Vitamin D analogues (calcipotriol, tacalcitol) – effective, with a lower risk of side effects than corticosteroids.
• Dithranol – used in so-called short-contact therapy at concentrations of 0.5–2%; it slows down skin cell proliferation.

Light therapy and systemic treatments

Systemic treatment is considered when psoriasis covers more than 10% of the body, when topical treatment isn’t working or when the condition significantly affects daily life. It is also used for pustular psoriasis, psoriatic arthritis and erythrodermic psoriasis.

• Narrowband UVB phototherapy (311 nm) – controlled exposure to a narrow band of ultraviolet light. It has an anti-inflammatory and immunosuppressive effect and is carried out under specialist supervision. A course of treatment usually lasts around 8–10 weeks, with two or three sessions a week.
• PUVA photochemotherapy – UVA light treatment combined with psoralen, a medicine that makes the skin more sensitive to light.
• Methotrexate – the most widely used cytostatic medicine for psoriasis. It requires regular monitoring of blood counts and kidney and liver function.
• Ciclosporin – a potent immunosuppressant used for severe and treatment-resistant psoriasis. Because it can damage the kidneys, kidney function and blood pressure need to be monitored regularly.
• Retinoids (acitretin) – normalise skin cell proliferation and are particularly useful in pustular psoriasis. They are highly teratogenic: women who could become pregnant must use contraception throughout treatment and for 3 years after stopping it.
• Biologics – the newest targeted treatments, acting on specific cytokines involved in psoriasis. They include TNF-α inhibitors (an older generation) and IL-17 and IL-23 inhibitors (a newer generation). They are given by injection or infusion and are prescribed and monitored by a specialist.

Is a sunbed a substitute for light therapy? No. A sunbed emits mainly UVA light, without a controlled dose, so it isn’t the same as medical narrowband UVB phototherapy – and it increases the risk of skin cancer. Dermatologists don’t recommend sunbeds as a way of treating psoriasis.

Psoriasis skincare: how to look after your skin

Skincare matters just as much during a flare-up as it does in remission. Chronic inflammation and accelerated shedding of skin cells seriously damage the hydrolipid barrier and increase TEWL – transepidermal water loss. The skin becomes dry, prone to cracking and more sensitive to external factors that can trigger the next flare-up.

Regular, gentle skincare helps rebuild this barrier, ease itching and flaking and keep the skin more comfortable between flare-ups. Well-chosen skincare products offer real support for your skin between visits to your dermatologist. Read more about how to repair your skin barrier step by step.

Emollients and other everyday skincare habits

• Skincare and clothing – avoid products with synthetic dyes and fragrance. Choose loose clothing made from natural fabrics that won’t irritate affected skin.
• Emollients twice a day – using emollients is standard dermatological advice for psoriasis. They help rebuild the hydrolipid barrier and limit TEWL, and can noticeably ease the symptoms of psoriasis.
• Don’t share your emollient – use your own jar or tube rather than sharing one with other people.
• Gentle cleansing – gels or foams without SLS and other harsh detergents or fragrance. Find out why skin feels tight after washing and how to cleanse without drying it out.
• Water temperature – lukewarm, not hot. Choose short showers over long, hot baths, which dry out the skin and can make symptoms worse.
• Sun protection – SPF all year round. Moderate sun exposure can ease psoriasis symptoms, but without proper protection the risk of irritation and flare-ups rises.
• Medicated shampoos – for psoriasis on the scalp, look for a psoriasis shampoo containing coal tar, sulphur or salicylic acid.

Skincare can’t treat psoriasis, but gentle formulas can support your skin barrier alongside the treatment recommended by your doctor or dermatologist. For everyday cleansing and moisturising, you can reach for Gentle Gel, Smoothing Cleanser or Cream – all free from fragrance and harsh detergents.

Psoriasis diet and lifestyle: what really helps?

Diet can’t replace treatment, but it can genuinely support it and help reduce the severity of symptoms. The foundation is an anti-inflammatory diet: rich in omega-3 fatty acids from oily fish, linseed and walnuts, as well as plenty of vegetables, fruit and wholegrains. Some studies also suggest that a vegetarian diet may have a positive effect on psoriasis.

When it comes to foods that trigger psoriasis, it’s worth cutting out alcohol and limiting simple sugars and ultra-processed food – in many people, these are the ones linked with flare-ups. What about gluten? A gluten-free diet only makes sense if you have coeliac disease or a confirmed gluten sensitivity – for everyone else, there’s no evidence that it helps.

Reducing stress is just as important. At least 7 hours of sleep a night and regular physical activity aren’t vague wellness tips: they have a documented effect on how the immune system responds.

How to ease psoriasis symptoms and prevent flare-ups

Preventing flare-ups: what to avoid

Because psoriasis tends to come and go, consciously avoiding your triggers is one of the most effective ways to keep remission going for longer. The first step is to treat any active sources of inflammation in the body – such as sinus infections, sore throats or tooth decay – which can set off the next flare-up.

In everyday life, it’s worth giving up smoking and alcohol and reducing stress. If you take NSAIDs or oral corticosteroids, talk to your doctor or pharmacist about whether they could be affecting your psoriasis – and don’t take them without a clear medical reason. Even in remission, when your skin looks good, using emollients regularly remains the foundation of care. It prevents the skin from drying out and keeps the hydrolipid barrier in good condition.

When to see a dermatologist

Don’t wait for your symptoms to get worse – see a dermatologist as early as possible. Diagnosing psoriasis early makes it easier to keep under control and reduces the risk of complications. Joint pain, swelling or stiffness are also warning signs: they may point to psoriatic arthritis, which, if left untreated, can cause permanent damage.

Seek urgent medical help if your skin suddenly turns red and becomes covered in pus-filled spots, or if inflammation spreads across most of your body together with a fever, chills or a racing heartbeat. These can be signs of a severe form of psoriasis or an infection.

Signs of psoriatic arthritis

Psoriatic arthritis causes pain, swelling and stiffness, most often in the finger joints, knees and spine. A characteristic sign is dactylitis, or ‘sausage fingers’ – an entire finger swelling evenly – along with pain where tendons attach to the bone. It affects around 10–30% of people with psoriasis, and skin and joint symptoms don’t always go hand in hand. If left untreated, it leads to permanent joint damage and reduced mobility, so any worrying joint pain in a person with psoriasis should be checked by a dermatologist or rheumatologist.

It’s also worth seeing a specialist if your current topical treatment has stopped working – this may mean your treatment needs to be changed or extended. And remember that psoriasis affects not only the skin but also your mental wellbeing. Psychological support and support groups aren’t an optional extra – they are a genuine part of treatment.

Aleksandra Kubas-Maliszewska

Frequently asked questions (FAQ)