What are psoriasis and psoriatic arthritis, and how are they connected?
Psoriasis and psoriatic arthritis are chronic, immune-mediated conditions that significantly impact quality of life. Psoriasis primarily affects the skin and nails, while psoriatic arthritis targets the joints. Despite their different primary manifestations, both conditions share an autoimmune origin and coexist in a significant percentage of patients.
The DocTIS project aims to enhance treatment efficacy in both along with other four immune-mediated inflammatory diseases (IMIDs): Crohn’s disease, ulcerative colitis, rheumatoid arthritis and systemic lupus erythematosus. Using high-throughput technologies and advanced systems biology, DocTIS seeks to identify safer and more effective therapeutic combinations compared to current single-drug treatments.
Psoriasis: causes and treatments
Psoriasis is a chronic, noncommunicable disease affecting 2–3% of the global population, with higher prevalence in Europe. It appears as red, scaly patches that can itch, sting, or cause pain. These lesions are typically symmetrical and well-defined, most commonly occurring on the elbows, knees, scalp, and lower back. Severity ranges from localized patches to widespread involvement, significantly impacting quality of life. In addition, moderate-to-severe psoriasis is frequently associated with obesity, metabolic syndrome, hyperuricemia and fatty liver diseases. Severe psoriasis, is also an independent cardiovascular risk factor, similar to other immune-mediated inflammatory diseases.
Psoriasis can develop at any age but most commonly at 20–30 and 50–60 years. Men and women are affected at similar rates, though some studies suggest women may experience more severe symptoms.
Psoriasis results from a combination of genetic, environmental, and immune factors. An overactive immune response accelerates skin cell turnover, although the exact triggers remain unclear. Stress, infections, and certain medications can provoke flare-ups, especially in those with a family history of the condition.
Common symptoms include:
- Red patches of skin covered with silvery scales
- Dry, cracked skin that may bleed
- Itching or burning sensations
- Thickened or pitted nails
Diagnosis is typically based on skin appearance, but a biopsy may be performed to rule out other conditions.
There is no cure for it, but treatments can help manage symptoms and reduce flare-ups. Topical treatments, such as corticosteroids and moisturizers, are often used to reduce inflammation and itching. In severe cases, light therapy or systemic medications (pills or injections) may be recommended to modulate immune responses.
Psoriatic arthritis: diagnosis and care
Psoriatic arthritis is another type of chronic inflammatory condition, linked to psoriasis, causing joint pain, stiffness, and swelling. If untreated, it can lead to joint deformities and disability. It most commonly affects adults aged 30–50, though it can occur at any age. Most sources estimate its prevalence to be around 1% of the global population.
Genetic predisposition and immune dysfunction are primary contributors, with inflammatory processes targeting joints, tendons, and ligaments. Environmental triggers, such as infections or physical trauma, may also play a role.
Common symptoms include:
- Swollen, tender joints
- Morning stiffness
- Fatigue
- Reduced range of motion
- Enthesitis (inflammation at tendon or ligament attachment points)
- Dactylitis (swelling of fingers or toes)
Diagnosis involves physical examination, medical history, and imaging (X-rays, magnetic resonance, or ultrasounds). Blood tests may help exclude other types of arthritis.
Treatment aims to reduce pain, prevent joint damage, and maintain mobility. Options include pain relievers, anti-inflammatory medications, and disease-modifying antirheumatic drugs (DMARDs) like methotrexate or biologic therapies. Physical therapy helps maintain joint flexibility and strength. Early treatment is essential to prevent long-term damage.
The link between psoriasis and psoriatic arthritis
Both conditions share an autoimmune origin, where the immune system mistakenly attacks the body’s tissues, causing inflammation in the skin, joints, or both. According to a 2019 article published in the Journal of the American Academy of Dermatology (and co-authored by DocTIS partner Paolo Gisondi from University of Verona and other global experts), about 19.7% of people with psoriasis develop psoriatic arthritis, often several years after skin symptoms begin.
Genetics significantly influences this connection, as having a family history of either condition increases the risk. Stress, infections, and physical injuries can also trigger or worsen symptoms.
Managing psoriasis effectively may help reduce the risk of developing psoriatic arthritis or lessen its impact. Early recognition of joint symptoms and prompt medical advice are crucial for preventing complications.
About DocTIS
DocTIS is a European-funded project aimed at developing personalized treatment protocols through the combination of existing drugs to minimize side effects and maximize efficacy for six immune-mediated inflammatory diseases. The project utilizes high-throughput technologies, including genomic and transcriptomic analysis, to identify biomarkers linked to treatment response. Advanced systems biology approaches are also employed to model complex immune pathway interactions and predict therapeutic outcomes. Project partners include renowned institutions such as Vall d’Hebron Research Institute (VHIR), Cardiff University, University of Verona, Charité – Universitätsmedizin Berlin,, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), the National Center for Genomic Analysis (CNAG), IIMIDomics Inc, HudsonAlpha Institute for Biotechnology, and Zabala Innovation.
(Above image by Freepik)
