Let's start by the definition: Psoriatic arthritis is an inflammation that involves the joints (arthritis) in someone who is having psoriasis. In many cases, individuals develop psoriasis first and then have psoriatic arthritis but the reverse can also occur.
The onset is usually between the age of 25 to 40 years old.
What is the cause of psoriatic arthritis ?The exact cause is unknown but it is most probably due to abnormal immune response which results in attacking the body's joints. This results in inflammation and if left untreated, can cause damage to the joints.
What are the different forms of presentations that can occur in psoriatic arthritis ?There are five main presentations for psoriatic arthritis:
1. Asymmetrical inflammatory oligoarthritis.
The joints of the upper and lower limbs can be affected. This will cause a painful, sausage-like swelling of the fingers and toes.
Notice the "sausage" middle finger.
2. Symmetrical polyarthritis.
There is symmetrical involvement of the small and large joints of the upper and lower limbs. This form predominates in women.
3. Predominant distal interphalangeal joint arthritis.
This is the most typical pattern of joint involvement in psoriasis. It mainly affects men. It is associated with nail dystrophy.
4. Psoriatic spondylitis.
Spondylitis is an inflammation of the joints between the vertebrae of the spine. This can manifest with lower back pain.
5. Arthritis mutilans.
It affects about 5% of patients with psoriatic arthritis. It is an erosive painful arthritis which affects fingers and toes and can cause a deformity.
(From Kumar and Clark's clinical medicine, 7th edition).
The prognosis in all, except arthritis mutilans, is generally good.
Advices to be followed during management:
- Exercise regularly and avoid prolonged rest.
- Maintain a normal body weight. Excess body weight can add loads to the joints.
- Avoid trauma and protect your joints.
There is no cure for psoriatic arthritis but the management lines are directed towards relief of symptoms and prevention of disability.
Different types of drugs are used in the management of psoriatic arthritis:
1. TNF alpha inhibitors: as infliximab and etanercept.
2. Methotrexate and sulfasalazine.
3. Azathioprine: it is an immuno-suppressant drug which suppresses the immune system which is attacking the body's own tissues (joints).
Feel free to post your questions by commenting on this post.