Psoriasis

Psoriasis is a chronic inflammatory condition that primarily affects the skin, although it can also affect the nails, joints and general health. Its course varies: some people have limited lesions, whilst others experience more extensive or persistent flare-ups.

What is psoriasis?

Psoriasis occurs when the immune system maintains an inappropriate inflammatory response in people who are predisposed to it.

This inflammation disrupts the skin’s normal renewal process. Cells in the outermost layer form and mature too quickly, build up and give rise to thickened, scaly patches.

Visible scaling is therefore a consequence of the inflammatory process and not simply an isolated excess of skin cells.

The condition usually progresses in flare-ups. Lesions may improve for a time and then reappear later, although some people experience more consistent symptoms.

Why it occurs

Psoriasis develops as a result of a combination of a genetic predisposition and an abnormal immune response. This predisposition may run in some families, but it does not follow a simple pattern of inheritance. Having relatives with psoriasis increases the likelihood of developing the condition, although many people affected are unaware of any family history of the condition.

The condition is not caused by poor hygiene, a skin infection or a particular emotional state. In some people, certain factors may contribute to the onset or worsening of a flare-up. In others, no clear trigger can be identified.

Factors that may contribute to flare-ups

Triggers vary from person to person and do not always have the same effect.

Among the best-known are:

• Certain infections.

• Skin injuries, burns or irritation.

• Intense or prolonged stress.

• Smoking and heavy alcohol consumption.

• Certain medicines.

The appearance of lesions on an area that has suffered an injury or irritation is known as the Koebner phenomenon. Stress can influence the course of the condition, but psoriasis is not a psychological condition and does not usually resolve solely through relaxation techniques.

Medicines that may exacerbate the condition should not be stopped without consulting a healthcare professional. The situation should be discussed with the healthcare professional who prescribed them.

What symptoms and lesions can it cause?

The most common form presents as well-defined, thickened patches covered with varying degrees of scaling. On fair skin, these patches usually appear pink or reddish. In darker skin tones, they may take on a purplish, brown or greyish appearance and leave pigmentary changes after they have cleared up.

The lesions may:

• Itch.

• Cause a burning sensation or pain.

• Crack.

• Bleed when rubbed.

• Cause little discomfort despite being visible.

They usually appear in a fairly symmetrical pattern and are common on the scalp, elbows, knees and lower back. They can also affect the face, skin folds, genitals, hands, feet and nails.

The intensity of the itching or pain does not always correlate with the extent of the lesions.

Main types of psoriasis

Plaque psoriasis

This is the most common form. It causes thickened, well-defined areas covered in scales. It can affect small areas or spread over larger areas. Its course usually alternates between periods of flare-ups and improvement.

Guttate psoriasis

It presents as numerous small, drop-like lesions, mainly on the trunk and limbs. It is more common in young people and may appear following a streptococcal throat infection.

It may resolve, recur or progress to plaque psoriasis.

Inverse psoriasis

It affects skin folds such as the armpits, the groin, the area under the breasts, the fold between the buttocks or the genitals. The lesions are usually smooth, shiny and show little scaling due to moisture and friction. It can be mistaken for a fungal infection, eczema or other skin irritations in these folds.

Palmoplantar psoriasis

It affects the palms of the hands, the soles of the feet, or both areas. Although it may cover only a small area, it can cause cracks, pain and difficulties with walking, working or carrying out manual tasks.

Pustular psoriasis

It produces small raised lesions filled with a whitish fluid as a result of inflammation. This does not necessarily mean that there is a bacterial infection. There are localised forms, particularly on the palms and soles, and other generalised forms, which are much less common.

When the lesions spread rapidly and are accompanied by a fever or general malaise, urgent medical attention is required.

Erythrodermic psoriasis

This is a rare form in which redness and scaling affect a large area of the skin. It can disrupt temperature regulation, fluid balance and the skin’s protective function. It is usually accompanied by general malaise and requires urgent medical attention.

Nail involvement

Psoriasis can affect one or more fingernails or toenails. It can cause small pits, discolouration, thickening, brittleness or separation of the nail.

It is not always merely a cosmetic issue. It can cause pain, make manual tasks difficult or interfere with walking. Some changes resemble those of a fungal infection, and both conditions can occur at the same time. Where there is any doubt, it may be necessary to analyse a sample before prescribing long-term antifungal treatment.

Nail involvement is also more commonly associated with psoriatic arthritis, although not everyone with nail changes will develop joint inflammation.

Psoriatic arthritis

Psoriatic arthritis may appear before, at the same time as, or after skin lesions. Early detection allows treatment to begin before permanent joint damage occurs. It can affect the joints, tendons and the areas where these attach to the bone.

Symptoms to look out for include:

• One or more swollen joints.

• Persistent morning stiffness.

• Pain or swelling in the heels.

• A finger or toe that is swollen along its entire length.

• Back pain that improves with movement.

• Progressive loss of mobility.

Joint pain on its own does not confirm psoriatic arthritis. However, a persistently inflamed joint or stiffness with inflammatory features requires assessment.

When it is important to seek medical attention

Most flare-ups of psoriasis are not a medical emergency. However, it is advisable to seek prompt medical assessment when lesions spread rapidly, affect a large area of the body or are accompanied by fever, chills, weakness or a significant deterioration in general health.

Generalised pustules, extensive scaling, severe skin pain or signs of dehydration also require prompt medical assessment. During treatments that modify the immune response, symptoms consistent with a serious infection should be assessed without delay.

It is also advisable to seek medical advice if a clearly swollen joint, a finger that is swollen along its entire length, or a progressive loss of mobility occurs, especially if these changes persist.

How psoriasis is diagnosed

The diagnosis of psoriasis is primarily clinical. The healthcare professional assesses the appearance and distribution of the lesions, their progression, the symptoms, any nail involvement, and the patient’s personal and family history.

There is no blood test to confirm cutaneous psoriasis.

Examination of the skin and nails

The shape, thickness, borders and location of the lesions usually make it possible to recognise the condition. The scalp, skin folds, palms, soles and nails are also examined, as some areas may go unnoticed.

Biopsy

A biopsy is not necessary in most cases. It may be carried out when the appearance is atypical or there is uncertainty regarding other inflammatory, infectious or neoplastic conditions.

It involves removing a small skin sample for examination under a microscope.

Differential diagnosis

Depending on its location and appearance, psoriasis can be mistaken for eczema, fungal infections or other inflammatory conditions. Confirming the diagnosis prevents inappropriate treatments from being continued for prolonged periods.

How severity and impact are assessed

Assessing the severity of psoriasis involves determining not only how much of the body is affected, but also where it appears, what symptoms it causes and to what extent it affects daily life.

The location of the lesions, the presence of pain or itching, whether the nails or joints are affected, and the response to previous treatments can significantly alter the assessment. For this reason, two people with a similar extent of the condition may require different treatment approaches.

Visible extent does not determine the full severity

A limited form of psoriasis may require more intensive treatment if it affects the hands, feet, face, genitals, nails or joints, or if it significantly interferes with daily life.

The following are also assessed:

• The thickness and inflammation of the plaques.

• Itching and pain.

• The location.

• Whether the nails or joints are affected.

• Response to previous treatments.

• The physical, emotional and social impact.

Localised psoriasis can be highly significant if it affects sleep, work, physical activity, intimacy or independence. In some clinical settings, scales such as the PASI are used to assess extent and severity, or the DLQI to estimate the impact on daily life.

These tools help to monitor progress, but they are no substitute for an individual assessment.

What is the treatment?

The aim of treatment is to reduce inflammation, manage symptoms, improve skin function and prevent joint damage. There is no single option that suits everyone.

The choice depends on the type and extent of the psoriasis, the affected areas, the presence of arthritis, previous treatments, other medical conditions, pregnancy or the desire to become pregnant, and personal preferences. In some cases, several treatment approaches are combined.

Topical treatments

Emollients help to reduce dryness, tightness and flaking. They complement anti-inflammatory treatment, although they do not usually control active psoriasis on their own. Topical corticosteroids reduce inflammation. Their strength, frequency of application and duration of use must be tailored to the specific area, as the skin on the face, genitals and skin folds is more sensitive.

Vitamin D analogues help to normalise skin cell activity and are frequently combined with corticosteroids. In sensitive areas, other anti-inflammatory medicines may be used in selected situations.

Keratolytic products help to reduce excess scaling, but are not suitable for all areas or for large surfaces. On the scalp, solutions, gels, foams, lotions or medicated shampoos may be used. The choice depends on the amount of flaking, the hair type and ease of application.

The treatment plan must be compatible with the person’s actual daily routine. A treatment that is too greasy, too frequent or too complex may prove difficult to maintain.

Phototherapy

Phototherapy uses ultraviolet radiation administered in controlled doses. The most commonly used form is narrow-band ultraviolet B radiation. It may be prescribed when the condition is extensive or does not respond adequately to topical treatments.

It usually requires several sessions per week over a specific period. It can cause redness, burns and cumulative effects on the skin, so the dose must be carefully monitored. Sunbathing on your own is not the same as receiving medical phototherapy.

Systemic treatments

Systemic treatments act on the whole body and are used when psoriasis is moderate or severe, affects highly visible areas, or does not respond to other options. Conventional treatments include methotrexate, cyclosporine and acitretin.

Methotrexate may be beneficial for the skin and for certain forms of peripheral arthritis. Cyclosporine can act quickly, but is usually used for limited periods. Acitretin may be effective for some forms of psoriasis and requires strict planning in relation to pregnancy. There are also targeted oral medicines that act on specific inflammatory pathways.

Biological treatments block specific signals that sustain the disease. They can achieve a very significant reduction in lesions in many people. There is no single biological treatment that is best for all patients. The choice also depends on the type of arthritis, other medical conditions, the risk of infection, previous treatments and the route of administration.

Before starting certain treatments, medical history, vaccinations and possible infections are reviewed. The necessary checks are carried out whilst the treatment is being used. A complete or almost complete improvement in the skin does not mean that the underlying condition has disappeared. Treatment should not be changed or stopped without prior consultation.

Nails and joints

Psoriasis affecting the nails usually responds more slowly than that affecting the skin. Where only a few nails are affected, topical treatments may be used. If it causes pain, loss of function or affects many nails, systemic treatment may be necessary.

Where psoriatic arthritis is present, the choice of treatment is coordinated with the Rheumatology department and takes into account the joints, tendons, spine, skin and nails. A medication that is effective for the skin is not always the most appropriate for all joint manifestations.

What happens if the response is inadequate?

Before changing the treatment, the diagnosis, dosage regimen, formulation, method of application and the possible presence of other skin conditions are reviewed. It is also assessed whether a limited area of psoriasis is in a highly visible area and requires more intensive treatment.

Any difficulty in maintaining frequent or uncomfortable applications should be reported. Adjusting the treatment plan is usually more helpful than attributing the inadequate response to a lack of consistency.

Progression and possible complications

Psoriasis is a chronic condition, but it does not follow the same course in everyone. It may manifest as flare-ups separated by periods of improvement, remain persistently active, or stay localised for years.

Not everyone develops extensive forms of the condition or psoriatic arthritis. Current treatments allow for a very high level of control, although adjustments, combinations or changes in medication may be necessary.

Psoriasis, particularly when it is more widespread or persistent, is more frequently associated with obesity, high blood pressure, abnormal cholesterol levels, type 2 diabetes, cardiovascular disease and fatty liver.

This association does not mean that everyone develops these conditions, nor that psoriasis is their sole cause. It can also affect sleep, self-esteem and emotional wellbeing, and may contribute to anxiety or depression. Assessing these aspects forms part of comprehensive care.

In which conditions or situations is this particularly important

The assessment must be particularly thorough when there are joint symptoms, extensive nail involvement or lesions on the hands, feet, face or genitals. The choice of treatment requires careful planning during pregnancy or when there is a desire to conceive.

Treatment may also need to be adjusted in the event of:

• Liver or kidney disease.

• Significant or recurrent infections.

• Inflammatory bowel disease.

• A history of certain cancers.

• Use of other treatments that affect the immune response.

These factors influence the pre-treatment tests, monitoring and choice of medication. Abrupt withdrawal of certain treatments, particularly systemic corticosteroids, should also be avoided without medical supervision.

How to reduce flare-ups and look after your general health

It is not possible to reliably prevent the initial onset of psoriasis or to avoid all flare-ups. Certain measures can help keep the skin in better condition and reduce factors that aggravate the condition:

• Follow the agreed treatment plan.

• Moisturise your skin.

• Avoid smoking.

• Limit or avoid alcohol consumption.

• Protect your skin from chafing and burns.

• Check for any medicines that may have an effect.

• Treat infections where medically indicated.

• Look after your metabolic health where necessary.

• Rest, physical activity and emotional support promote general health and can help you cope better with the condition.

There is no one-size-fits-all diet that cures psoriasis. Dietary changes should be tailored to individual needs and not based on promises to eliminate inflammation through unnecessary restrictions.

Which specialists treat psoriasis

The management of psoriasis may require the involvement of various specialists, particularly when it affects several areas of health or requires systemic treatments.

Dermatologists confirm the diagnosis when there is any doubt, assess the extent and impact of the condition, and supervise topical treatments, phototherapy and systemic therapies.

Rheumatologists become involved when there are symptoms consistent with psoriatic arthritis or when this has already been diagnosed, coordinating the treatment of joint involvement with dermatology specialists.

Primary care may be involved in the initial detection and follow-up of mild cases. Depending on each individual’s needs, professionals from nursing, hospital pharmacy, psychology or nutrition may also be involved.

Within our hospital’s Dermatology department, we have an Immunomedicated Inflammatory Diseases Unit, dedicated to the specialised management of conditions such as psoriasis and to coordinating follow-up and treatment when the complexity of the condition so requires.

Living with psoriasis

Living with psoriasis involves more than just managing visible lesions. Itching, pain, the location of the plaques, the need for ongoing treatment and the impact on sleep, work, intimacy or self-esteem can affect each person in very different ways.

Adapting treatment to everyday life, identifying which aspects cause the most disruption and addressing them specifically are all part of managing the condition.

Symptoms and daily life

Itching can disrupt sleep. Flakes may be visible on clothing. Lesions on the hands and feet can make work, exercise or everyday tasks difficult. The condition can limit activities even when it affects only a small area of the skin.

Intimacy and relationships

Genital psoriasis can cause pain, irritation and difficulties with intimacy. It is not contagious and is not transmitted through sexual intercourse or physical contact.

Discussing these symptoms during your consultation allows the treatment to be tailored to this particularly sensitive area.

Treatments and routine

Some topical treatments are greasy, take time to work or are difficult to apply to the scalp and over large areas. Adjusting the texture, timing or frequency can make it easier to incorporate them into daily life.

The choice should strike a balance between effectiveness, safety and ease of use.

Emotional wellbeing

Stigma, stares or comments can affect self-esteem and lead to social isolation. Psychological support is not intended to treat a supposed emotional cause, but rather to help cope with the impact of a chronic and visible condition.

There are no universal restrictions on playing sport, swimming in pools, engaging in physical contact or enjoying a sex life. Any adjustments will depend on pain levels, the location of lesions, the presence of fissures and the treatment being used.