Psoriatic Arthritis: Causes and Manifestations of Psoriasis with Joint Infection

Psoriatic Arthritis: Causes and Manifestations of Psoriasis with Joint Infection
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Psoriatic arthritis is a long-term progressive inflammatory disease combining psoriasis with joint damage.


Psoriatic arthritis is a progressive chronic inflammatory disease that combines psoriasis with joint damage. The basis is a rheumatic and autoimmune process, in which the immune system attacks its own cells.

A person with psoriasis may also experience joint damage, and in some cases, extra-articular problems, e.g. vision impairment, and skin changes.

Rheumatic diseases are associated with a certain genetic predisposition and the presence of certain antibodies.

Autoimmunity is the result of an immune disorder when the body's own cells, tissues and structures are attacked by immunity.

Progressive disease means that it is a progressive problem that develops and worsens over time.

Psoriasis is a skin disease that we also know as psoriasis. The name is derived from a typical skin symptom, i.e. hardening of the skin, redness and the formation of scales that peel off.

Arthritis is an inflammatory process that affects the joints. It can have a different course and often leads to total destruction of the joint and its deformity.

Of course, it is associated with pain and other unpleasant problems that limit a person's daily activities. In addition, the fact of aesthetics is also attractive. The disease reduces the quality of life and affects the sufferer's mental health.

Fortunately, psoriasis and psoriatic arthritis are well-treatable diseases. However, it cannot be cured completely.

Early detection and timely treatment are important. Otherwise, there is a risk of increased morbidity and shortened the life expectancy of the affected person.

Some interesting facts: 
Psoriasis affects 1-3% of the world's population.
The incidence of psoriatic arthritis in psoriatic patients is reported to be about 10-42%.
That is 0.2 to 1% of the world's population.
As many as 75% of cases first show signs of skin manifestations, 
and the onset of joint problems can last up to 10 years.

Psoriasis + Arthritis = Psoriatic Arthritis

Psoriasis is a skin disease with an unknown cause. Certain risk effects and preconditions leading to the onset of an autoimmune reaction are involved in the development of the disease.

An indeterminate trigger is sufficient to trigger health problems.

Psoriasis is manifested by a chronic inflammation of the skin. The skin eventually gets thicker, red, cracked, and develops superficial scales, which peel off.

In some cases, joint damage is associated with skin damage. Several authors report the figures to range from 6 to 42%.

The disease sometimes has a typical course, i.e. mild to inconspicuous, but in some cases it is critical with total destruction of the joints that leads to disability.

Psoriatic arthritis is a chronic progressive inflammatory disease of the joints associated with psoriasis.

Psoriatic arthritis is also referred to by its abbreviation, PsA.

Extra-articular problems, i.e. other than joints, are also a risk.

It usually develops after the age of 30. It can also affect a child. In general, except for a certain subtypes, it affects both men and women equally.

Joint damage mainly affects the small joints of the hands and feet, but, in the case of a more severe form, we can also observe signs on the spine.

It is also a seronegative spondylarthritis, similar to ankylosing spondylarthritis - Bechterev's disease.

Prevalence estimates in Europe range from 0.05% in Turkey and the Czech Republic 8 to 0.21% in Sweden. Only a few reports of the prevalence of PsA in South America and Asia exist and suggest that the prevalence is lower in these regions (0.07% in Buenos Aires and 0.02% in China). Source: The Epidemiology Psoriatic Arthritis.

PsA can shorten the patient's life by an average of 3 years.

It also has a negative effect on the person's mental health, while appropriate treatment can make a return to normal life possible.

Want to know more about this rheumatic disease?
What are the typical signs and symptoms?
What are the risk factors?
What are typical manifestations?
Is there a treatment?


Psoriatic arthritis is a systemic inflammatory disease whose exact cause is unclear. Inflammation is an autoimmune process in which immunity destroys the body's own cells.

At the outbreak of the disease, certain underlying conditions and the influence of external factors come together. So, there are multiple causes.

Multifactorial basis and risk factors in the development of PsA:

  • genetic predisposition
    • family history - it is assumed that the offspring may develop the disease, but there is no direct inheritance if the father has psoriasis, the child may have it, too, or in the form of PsA.
  • psoriasis
  • presence of HLA antigens
  • infection, such as a virus or bacteria
  • medications (antimalarials, lithium, beta-blockers)
  • stress and long-term mental strain
  • injury
    • Koebner phenomenon - appearance of skin lesions after an injury due to mechanical stress and physical and chemical effects
  • hormonal influence
  • age, especially between 30 and 50 years of age
  • being overweight and smoking, excessive alcohol consumption also contribute negatively
  • dry skin

Psoriasis and psoriatic arthritis are not contagious.
PsA is a non-infectious disease.


Symptoms of psoriatic arthritis include two main groups of manifestations, namely the skin and joints.

In some cases, the presence of difficulties outside these two areas is also a risk. An example is damage to the eyes as well as the cardiovascular system.

Not everyone develops the same picture of the disease, ie it has individual manifestations. However, it is characterized by certain characteristics.

Psoriatic arthritis has several subtypes.

Table: Distribution of Psoriatic Arthritis Based on Symptoms and Course

Subtype Symptoms
Asymmetric PsA it is also referred to as the oligoarticular form
  • more frequently occurring type of PsA
  • affects the joints on one side of the body
  • joint pain and joint swelling
  • joint stiffness
  • the joints of the upper and lower limbs of the hand + legs are affected first
    • DIP - distal interphalangeal joints, i.e. the lower inter-articular joints of the fingers and toes
    • PIP - proximal interphalangeal joints - upper inter-articular joints of the hand and foot
    • and small joints of the hand and foot (MCP - metacarpophalangeal and MTP - metatarsophalangeal joints)
  • the presence of dactylitis is typical - swelling of the fingers resembling a sausage or sausage-like fingers
  • less frequently hip joints, knees, ankles, wrists
  • approximately 35% of cases
Symmetric PsA
  • polyarticular form
  • the disability is on both sides of the body and in the same joints
  • similarity to rheumatoid arthritis
  • often affecting the small joints of the hands and feet
  • including knees, ankles, elbows
  • the most common form of PSA - about 50% of PsA cases
  • disability of 3 or more joints
  • affects women more often
Damaged distal interphalangeal (DIP) joints
  • inflammation of the lower inter-articular joints - finger joints closest to the nails
  • DIP - distal interphalangeal joints
  • in most cases it is associated with nail psoriasis
  • about 10% of cases
Arthritis mutilans
  • the worst course of arthritis
  • arthritis mutilans
  • loss and disintegration of the joint
  • deformities of fingers, limbs
Axial form
Sine syndrome in PsA
  • DIP and dactylitis
  • lacking joint involvement
  • a significant familial occurrence of psoriasis in a family member, but a missing component of psoriasis in PsA
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Psoriatic arthritis presents with the following symptoms:

  • joint pain and joint sensitivity
    • mainly small joints of hands and feet, toes
    • knees
    • ankles
    • thighs
    • sometimes the spine
  • swelling of the joints - swelling of the fingers resembles sausages - sausage digits
  • morning stiffness of the joints - the pain is relieved by warm-up, retreats after waking up, worsens due to inactivity
  • impaired joint function - for example, poor hand grip, less range of motion, reduced force, and the like
  • erosion of the skin of fingers, nails
  • and other skin manifestations
    • reddness on the skin
    • itching
    • dry skin
    • thickening of the skin
    • formation of white scales and their peeling + psoriasis on the joints
    • mainly in the elbows, knees, back, scalp
  • nail psoriasis, separation of the nail from the nail bed
  • pain in tendons and their attachments, such as Achilles tendon pain, heels, feet
  • deformities of limbs, fingers, shortening of fingers, telescopic fingers
    - worse course of the disease due to neglected treatment or a severe form of the disease
  • inability to move in the affected joints
  • it can be associated with more extra-articular and extracutaneous problems
    • tiredness
    • inflammation of the entheses (tendons or ligaments) - enthesitis
    • inflammation of the eyes, conjunctivitis - conjunctivitis, uveitis, itchy eyes, redness and the like - common associated symptom, about 30% of PsA cases
    • aortic valve damage - about 4% of cases
    • risk of hypertension and other cardiovascular diseases
    • chronic bronchopneumonia
    • intestinal inflammation - nonspecific inflammatory bowel diseases (IBD),
      form with ulcerative colitis or Crohn's disease
    • osteoporosis
    • depression and mental disorders - very frequent


The basis of diagnosis is the patient's medical history. Describing symptoms lead to suspicion of rheumatism.

This is followed by a thorough examination of the skin, joints, nails - the presence of defects, redness, depressions in the nails, ulcers in their vicinity. There may also be some sensitivity in the area of tendon attachments.

Laboratory blood tests are added, CRP and sedimentation are increased in inflammation, antibodies, blood counts and others are determined.

It is worth noting that Rheumatoid Factor - RF, which is present in rheumatoid arthritis (RA), is not present in psoriatic arthritis (PsA)

The presence of RF is a hallmark in distinguishing the two diseases,
i.e. rheumatoid arthritis RA from psoriatic arthritis PsA.

The synovial fluid may be taken from a larger joint, such as the knee. This helps the differential diagnosis as it is important to determine the type of disease.

Imaging methods that assess bone and joint damage are important, e.g. X-ray, CT, MRI, sonography.

The CASPAR (ClASsification criteria for Psoriatic ARthritis) criteria from 2006, which evaluates the presence of symptoms, is helpful in diagnosis. Namely, the presence of psoriasis, nail damage, the absence of RF in the blood, the presence of dactylitis and X-ray evaluation.

Psoriatic arthritis is to be suspected in the following cases:

  1. pain in the joints and tendons of the tendons
  2. swelling of the joints, attachments and fingers
  3. morning stiffness of the joints
  4. fatigue - persistent and intense
  5. inflammatory back pain
  6. association of extra-articular symptoms


There is considerable variability in the course of psoriatic arthritis. The course of the disease is individual, including the onset of the disease.

Mostly, about 75% of cases develop with the initial onset of skin changes - psoriasis. Joint problems start later and indefinitely. It may sometimes take 10 years for a full PsA to develop.

Onset = skin changes. 
Joint manifestations up to 10 to 20 years later.

Less frequently, there is a simultaneous onset of skin and joint problems. Joint problems precede psoriasis to an even lesser extent.

The course may be associated with sine psoriasis in PsA - if there is an inflammation of the joints, but no skin manifestations of psoriasis. However, a relative suffers from psoriasis or PsA.

Severe or mild.

In psoriatic arthritis, a mild course is possible when the difficulties are less severe. Over time, remission occurs, i.e. the reduction or disappearance of the signs and symptoms of the disease. This period, relatively without PsA, alternates with relapse, i.e. a recurrence of a past condition.

The opposite is an acute course or associated severe joint damage. Such a form can culminate in the destruction of the joint or its immobilization and deformation, shortening of the fingers and the like.

If the disease takes a severe course, there will be a significant reduction in daily activities and quality of life of the affected person. The patient is not able to button up or grab objects, or be self-sufficient. The disease is debilitating, especially when the joints needed for movement are damaged. The patient cannot walk up the stairs, and walks with great difficulty.

Typically, the most pain in PsA is caused by morning inflammation. This is accompanied by morning stiffness of the joints, which usually lasts about 30 minutes to an hour. Rarely for a long time.

Pain may or may not be associated.

The symptoms are alleviated by movements, and worsened by inactivity.

The colour of the skin above the joint changes. In addition, skin defects with psoriasis are present, there is also nail damage.

Swelling is a common manifestation of inflammation of the joints, tendons and their attachments.

The patient complains of swelling, pain, stiff and weak limb, such as a hand. Grabbing things with the palm is often not possible. In other cases, the affected location is painful, there is weakness in the hips, thighs, knees, ankles, wrists and on the back.

The onset of PsA symptoms is usually characteristically slow, like in rheuma. The provocative stimulus may be an injury, stress, post-infection and the like.

There may be one or more joints affected, 1-3 joints are indicated. There may be up to 5 joints. It depends on the subtype.

Sometimes back pain is associated. Redness of the eyelids and their inflammation are common.

The course is exacerbated by late detection and failure to treat early.

Read also: Seborrhea - Seborrhoeic dermatitis: Manifestations and Treatment

How it is treated: Psoriatic arthritis

Treatment of psoriatic arthritis: medications and other therapies

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Interesting resources

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