Understanding Autoimmune Conditions: Psoriatic Arthritis Fundamentals
Medically Reviewed by Carolin Schneider, MD
Psoriatic arthritis is a condition that occurs when someone who has psoriasis — an autoimmune skin condition — also develops the joint and bone condition arthritis. Around 30% of people with psoriasis experience psoriatic arthritis at some point in their life. Psoriatic arthritis typically affects joints in the fingers or toes, which are often described as looking “sausage-like” with nail deformities. Psoriatic arthritis may also affect the lower back, wrists, knees or ankles. If you live with psoriasis, learn more about psoriatic arthritis to better understand how the condition affects people and what treatment options exist.
Causes and Symptoms of Psoriatic Arthritis
There are five types of psoriatic arthritis. These include:
- Symmetrical: Symmetrical psoriatic arthritis affects several joints, but they’re the same joints on both sides of the body. For example, if one of your wrists is affected, your other wrist will be as well with symmetrical psoriatic arthritis. It’s generally milder with more minor deformity, and symptoms resemble those of rheumatoid arthritis.
- Asymmetrical: This type of psoriatic arthritis affects fewer joints on one or both sides of the body. Fingers and toes may be enlarged and tender.
- Distal Interphalangeal: Distal interphalangeal psoriatic arthritis (DIP) is known as the “classic” type of psoriatic arthritis. It primarily affects the joints of the toes and fingers closest to the nail, resulting in deformed nails and nail beds.
- Arthritis Mutilans: Arthritis mutilans affects small joints in the hands and feet and is the rarest form of the five types.
- Axial Arthritis: Axial arthritis affects the spinal column between the neck and the lower back.
The risks of psoriatic arthritis increase with age, just like all arthritis types. It most commonly affects people between ages 30 and 50 years old, and men are more at risk than women. If you have a sibling who’s been diagnosed with psoriatic arthritis, you also have an increased risk of developing the condition. People who already have psoriasis skin conditions have a higher rate of developing psoriatic arthritis as well. The skin condition typically precedes the development of arthritis. Despite this, it’s essential to note that not every person who has psoriasis will develop psoriatic arthritis.
Symptoms of psoriatic arthritis can include, but aren’t limited to:
- Joint tenderness and swelling similar to the feeling of tendonitis
- Back pain
- Swelling of fingers and toes
- Muscle pain
- Joint pain
- Abnormal nail changes, such as pitting, ridging or separation of the nail from the nail bed
- Discoloration of the nails, similar to that of a fungal nail infection
- Morning stiffness in the joints
- General fatigue
- Reduced range of joint movement
- Redness and pain around the eyes
Initially, symptoms usually happen in acute episodes. You may have short, sudden periods of worsening symptoms that alternate with periods of no signs. If you already have psoriasis, be sure to let your healthcare provider know if you start experiencing any of the symptoms listed above.
Diagnosing Psoriatic Arthritis
There’s no definitive method for diagnosing psoriatic arthritis. Because psoriatic arthritis has many overlapping symptoms that occur with other forms of arthritis, healthcare providers usually perform several tests and confirm a diagnosis of psoriatic arthritis via the process of elimination.
- Health History: A doctor may ask you routine questions related to your personal and family health history, including questions about your skin, to identify whether you have psoriasis.
- Physical Examination: Your doctor will perform a physical examination to rule out symptoms of other forms of arthritis. Here, the doctor may conduct an examination to test your range of motion and flexibility. These tests are part of routine physical exams and you may need to do them at several different appointments so your doctor can track any changes over time.
- Blood test: After having a physical exam, your provider will likely do a blood test to help further eliminate a diagnosis of another condition. For example, your doctor may run a blood screening to test for antibodies that are often present in different types of arthritis.
- Joint Fluid Testing: If you’re experiencing joint pain, your provider may take a sample of the fluid in the affected joint and test it to rule out the presence of gout.
- X-ray: X-rays can help diagnose psoriatic arthritis after the condition has advanced somewhat. Doctors may look for an X-ray phenomenon unique to psoriatic arthritis known as the “pencil-in-cup” formation. In this case, the end of the bone near the joint has degraded and narrowed to a sharp point instead of the rounded end typical of normal joint bones. Changes in the position of the spine can also support the diagnosis of psoriatic arthritis. Keep in mind that X-rays cannot detect the disease during its early stages.
While some primary care physicians and dermatologists can treat symptoms of psoriatic arthritis, it’s best to seek out a rheumatologist — an arthritis specialist — to ensure you get a proper diagnosis.
Treating Psoriatic Arthritis
While there’s no cure yet for psoriatic arthritis, treatment plans can help alleviate symptoms and possibly prevent further joint damage. Treatment depends on how severe your symptoms are, and your doctor will create a customized treatment plan based on your individual case.
- Physical Therapy: A doctor will prescribe you physical therapy to learn movement routines that may help your joints feel and work better in the long run. Rehabilitation can also maximize the functions of your affected joints through targeted physical therapy.
- Medication: In severe cases, anti-inflammatory drugs, along with additional therapy, may be prescribed in pill form or intravenous (IV) infusions to help reduce swelling, joint pain and stiffness.
- Surgery: In more severe cases, surgery can also be an option. However, medications and surgery also come with side effects and risks, so it’s essential to consult with your physician beforehand about whether this is the right option.
- Supplements: You may opt to take calcium supplements with vitamin D as a preventative measure against developing other forms of arthritis in the future. Talk to your doctor first before taking any supplements.
- Exercise: Exercise can help you build muscle strength, maintain your range of motion and reduce joint stiffness.
- Additional Therapy: Your provider may also recommend wearing splints and shoe inserts to help support your spine. Warm, stable climates have been shown to reduce symptom episodes, and cold packs may help reduce swelling of sausage-like digits.
If you experience symptoms of psoriatic arthritis, consult your doctor for help in pursuing a diagnosis. Psoriatic arthritis can impact your quality of life, especially if you’re younger than middle age. Talk to a medical professional about any symptoms of depression or sadness that you experience. Your doctor can provide resources and work with you to improve your quality of life.