Psoriatic Arthritis (Psoriasis Arthritis) ICD-10: L40,5, M07

 Definition

Psoriatic arthritis is rheumatoid arthritis (Arthritis) with joint and back disease affecting 5-10% of those with psoriasis in the skin

• Most often is psoriasis in the skin first present
• Psoriatic arthritis is a rheumatic inflammation that is classified among spondyloarthritis, but not counted among connective tissue diseases or vasculitides
• By suspected refer to rheumatologist for further consideration

Symptoms

• Psoriasis in the skin or scalp
• Nail abnormalities
• Joint stiffness
• Arthritis (Arthritis)
• Pain
• Instable joints
• Reduced joint mobility
• May cause eye complications

Various types of psoriatic arthritis

Small joints are attacked

• Fingers, especially outer joints (DIP), thumb's outer joints (IP) and middle joints (PIP). Nail psoriasis coexist with external joint affection

Asymmetrical arthritis

• Multiple joints swell up, most large joints like knees, ankles, elbows

Symmetrical arthritis

• Small and large joints
• Similar to rheumatoid arthritis but not manifestation in the α-CCP

Mutilans

• Rare (5%), but destroys joints in fingers and feet

Spondylitis

• Looks like Bekhterevs (ankylosing spondylitis), but the tissue type (blood sample) HLA-B27 occurs only in about 50% (more than 95% have HLA-B27 at ankylosing spondylitis, about 8-15% in the general population)

Classification criteria 

(CASPAR = Classification Criteria for Psoriatic Arthritis, Reference: Helliwell PS, 2005)

At least three of the following five points:

1. Proven psoriasis (one of A, B, C)
   1. Current psoriasis
   2. Disease history of psoriasis
   3. Family history of psoriasis among first- or second-degree relatives
2. Psoriasis nails dystrophy (including onycholysis, pitting and hyperkeratosis observed by a doctor)
3. Negative test for RF (rheumatoid factors)
4. Dactylitis (one of A or B)
   1. Ongoing symptoms
   2. Disease history (documented by rheumatologist)
5. Radiologically proven juxtarticular (near joints) new bone formation (not osteophytes)

Treatment

Before treatment starts, it is important to be informed about the disease, what the treatment target is and about the side effects that may occur. Treatment goal is to stop the disease completely, ie obtain remission. Unfortunately, there is no treatment that heals the disease.

• Treatment of symptoms with Ibux, other NSAIDs or mild pain-relieving drugs
• Joint fluid drainage and cortisone injections in large swollen joints
• Methotrexate
• Biological treatment
• Apremilast (Otezla)
• More about treatment EULAR guidelines, reference: Smolen JS, 2018)
• Other literature on treatment here: reference: Kang EJ, 2015)

Literature

• Gladman D, 2016
•  Wikipedia (English)

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