The skin is made up of several layers, from a very thin outer layer of dead cells, to
the very inner layer of skin. The skin normally regenerates itself completely over the
course of approximately a month, from the outer layers to the lower layers. The new
skin underneath replaces the layer on top of it, at the same time as the outer layer
of dead skin cells are sloughed off.
In patients with psoriasis, however, part of this process happens much too fast. The
skin regenerates instead in a matter of days, and the layers of skin cells cannot be
sloughed off quickly enough. The buildup of these dead skin cells then causes thick, itchy
patches on the body. The most prominent symptoms are these resulting dry, scaly patches of
skin. The areas may be cracked or raised, and covered with silvery scale-looking spots.
The area around the patches may be red, with small pustules, or blisters. These patches
are often itchy and sore. The most common areas that are affected by psoriasis are the
elbows, knees, skin folds, and trunk, but it can affect the skin anywhere on the body.
Patients may also experience problems with their toes or fingernails, and/or burning and
itching eyes.
There are known triggers for flare-ups of psoriasis, though the cause is not completely
known. Injury to the skin, such as scrapes or cuts, insect bites, or other rashes, can
aggravate the symptoms of psoriasis. People, who are immunosuppressed due to chemotherapy,
AIDS, or other diseases such as rheumatoid arthritis, are also at risk for more severe
symptoms. Many other factors, such as alcohol, lack or overexposure to sun, and stress can
contribute to flare-ups of the disease. The disease is not contagious.
Your doctor may take a skin biopsy of one of the scaly patches, and/or order blood
tests to make a diagnosis of psoriasis. Most commonly, however, diagnosis will be made
based on the medical history and the examination of the skin and/or nails.
The 5 Types of Psoriatic Arthritis and their symptoms
There are actually five types of psoriatic arthritis, each with different symptoms,
disease course, and treatment. The majority of people with psoriatic arthritis experience
only mild arthritis symptoms, and in only a few joints. The most common type causes
symptoms in one or two joints only. For those who do experience more severe symptoms,
however, such as in the spine, the symptoms are usually able to be treated with
medications and other therapy.
Distal Interphalangeal Predominant
This type of psoriatic arthritis primarily affects the last joint of the fingers and
toes (the distal interphalangeal joint. It is similar to osteoarthritis, and
in fact often mistaken for that type, though the symptoms are generally limited to these
joints only.
Asymmetrical Arthritis
Asymmetrical arthritis generally only affects two or three joints, and individually
rather than in pairs. It can affect any joint in the body, though it is common in the
fingers and toes. It often causes what your doctor may refer to as sausage
digits, where your fingers swell. The joints are often red and warm to the touch.
This type is quite common, affecting 55-70% of patients with psoriatic arthritis. It is
generally mild, though, and doesnt progress as much as some of the other forms. It
is fairly responsive to treatment with NSAIDs and other drugs.
Symmetrical Polyarthritis
Symmetrical polyarthritis, also referred to simply as symmetrical arthritis, is
identified by the fact that joint swelling tends to occur in pairs, on both sides of the
body. For instance, if the elbow is affected, both elbows will be affected. It resembles
rheumatoid arthritis, though it is less severe. It is probably the second most common in
patients with psoriatic arthritis, affecting 15-70% of patients. It can be severe and
cause joint deformity, and the skin symptoms are often much more severe than in those with
other types.
Spondylitis, or Psoriatic Spondyloarthritis
Spondylitis refers to inflammation of the joints in the spine. This is a serious
condition that can cause deformity and changes in posture as a result. It is less common
than the previously- mentioned types, affecting from 5-33% of those with the disease. In
addition, patients with this form of psoriatic arthritis often experience symptoms in the
joints in the arms and legs. The most prominent symptoms of this type include
inflammation, tenderness, and stiffness in the joints of the joints in the back and neck.
It can actually affect the ligaments in these areas as well.
Arthritis Mutilans
Arthritis mutilans is a very severe type of psoriatic arthritis. It is fairly rare,
affecting less than 5% of patients who are diagnosed with psoriatic arthritis. Its
severity is due to the fact that it actually destroys bone and cartilage in the joints,
deforming the joints in the hands and feet primarily. It tends to come and go in a series
of exacerbations, or flares, and remissions. These often coincide with flares in the skin
symptoms.
Patients may have one or more of these types during the course of their disease, and
may actually show signs of several types at once, so that identification of a single type
is not always possible. In addition, there are three other forms of arthritis that may
occur in patients with psoriasis: Reiters syndrome, gout, and rheumatoid arthritis.
Reiters syndrome is a disease that causes inflammation of the urethra, inflammation
in the eye, and arthritis. It is not a venereal disease but it does produce lesions on the
genitals, as well as the palms of the hand, soles of the feet, and in the mouth. Gout is a
form of arthritis that causes inflammation and sudden attacks of severe pain, often in the
big toe. It results from excess uric acid in
the blood, which causes crystals to form in the affected joints. In patients with
psoriasis, the condition is generally only present for a short time.
Where joint deformity occurs in one of the above- mentioned forms of psoriatic
arthritis, the condition may be easily confused with rheumatoid arthritis, which is a type
of arthritis associated with the immune system that causes severe deformity of the joints.
These types are distinguished from rheumatoid arthritis primarily by the absence of a
particular antibody found in the blood of most patients with rheumatoid arthritis, known
as the rheumatoid factor, in addition to the skin symptoms. Rheumatoid arthritis may occur
in patients with psoriatic arthritis as well, however. Your doctor will use diagnostic
tests such as blood tests and x-rays of the affected joints to help determine what type or
types of arthritis you have.
Causes of Psoriatic Arthritis
The cause of psoriatic arthritis is unknown. Doctors suspect that genetic,
environmental and immune factors play a role in the condition. It is classified in the
group of diseases called Seronegative Spondyloarthropathies. Approximately 40 percent of
people who develop psoriatic arthritis have a family member with either psoriasis or
arthritis.
Psoriatic arthritis symptoms
There is no cure for psoriatic arthritis. Treatment programs are tailored to the
individuals symptoms, in order to manage them most effectively. Because the course
of the disease can be very different from patient to patient, factors such as remissions
and exacerbations of symptoms are also important to take into consideration. Every patient
is different, and our treatment program will be tailored to your own particular needs.
Treatment plans include reducing inflammation in the joints, reducing pain, and
preventing further damage. Psoriatic arthritis is actually treated in much the same way
that the conditions of psoriasis and arthritis are treated individually. The skin is
treated with topical and oral medications, including antibiotics. One aim in patients with
psoriasis is the prevention of secondary infections as a result of the skin irritation.
Mild forms of the accompanying arthritis are treated like other forms of arthritis,
using aspirin, anti-arthritis drugs and other medications. Non-steroidal anti-inflammatory
drugs, or NSAIDs, are used to control the pain and swelling of the arthritis. Your doctor
may inject steroids directly into affected joints instead of prescribing medications for
you to take at home. In patients for whom this is not therapeutic, other drugs may be
prescribed. These include methotrexate as well as an antimalarial drug known as
hydroxychloroquine. Unfortunately some drugs used to treat one set of symptoms,
particularly those that are classified as antimalarials, can trigger an exacerbation, or
worsening, in another set, so it is especially important that you talk to your doctor
about any side effects you have from the drugs. It is also important to understand that
there doesnt seem to be any link between the location of skin symptoms and the
location of joint symptoms. You may have scaly patches on one part of your body, and joint
pain and swelling in an entirely different part. It is not known what the link is between
these two conditions.
There are also some therapeutic treatments that can ease some pain and swelling in your
joints, such as heat, cold, or soaking in warm water. It is important to get sufficient
rest. Your doctor may also suggest an exercise program tailored to your condition, to
improve your general health as well as your joint health.
Other more aggressive treatments include corticosteroid injections into the joints or
injections of gold salts for patients with more destructive joint damage. In the case of
very severe joint damage, surgery may be necessary, but it is not common. One of the
concerns the surgeon has is the worry of infection of the joint by going through skin
lesions overlying the affected joint.
Your doctor may refer you to a rheumatologist for specialized treatment for your
condition. A rheumatologist is a doctor who specializes in rheumatic diseases, or diseases
of the joints. While psoriatic arthritis is not entirely rheumatic in nature, a
rheumatologist may nevertheless be very helpful in prescribing the best course of
treatment for patients.
Your doctor may also refer you to a dermatologist, a doctor who specializes in diseases
of the skin, for treatment of your psoriasis.
With proper understanding of your condition, and good medical care, you should be much
better able to assist in your own treatment. By understanding the various factors that can
cause flare-ups in your symptoms, you can avoid these and minimize the effects on your
body.
Finally, if you have any questions about your disease, additional symptoms not
mentioned here, or your treatment plan, you should consult with your doctor.