There are several symptoms and signs that can help us sort out rheumatoid arthritis from psoriatic arthritis. You don’t have to have all those symptoms and signs together. You need to have some of them. We weigh the strength of each of those symptoms and signs in the process of sorting out rheumatoid arthritis from psoriatic arthritis. 

Number 1:

the pattern of joint affection. Rheumatoid arthritis tends to affect the joints of both sides in a symmetrical fashion unlike psoriatic arthritis that tends to be asymmetrical. This is not a rigid rule though and exceptions can exist of course and it’s up to the evaluation and assessment of the doctor to what extent he/she can rely on that sign.

Number 2:

Psoriatic arthritis, in one of its patterns of joint affection, loves to inflame the distal row of the joints of the fingers and rheumatoid arthritis does not show much interest in that row of joints. If this is the pattern of joint affection in a patient with psoriatic arthritis, it really helps a lot in the differentiation process.

Number 3:

 In fifty percent of psoriatic arthritis patients there is not much stiffness of the joints in the morning unlike rheumatoid arthritis where morning stiffness is a more recognized symptom.

Number 4:

Sometimes, patients with psoriatic arthritis will get what we call sausage digit. This is inflammation of all the tissues of a finger or a toe. The joints and the tendons and even the soft tissues of that finger or that toe in that case are swollen and look like a piece of sausage. This sign, if present, is very much diagnostic or suggestive of psoriatic arthritis.

Number 5:

Having psoriasis of the skin or nails or scalp. If you have psoriasis, skin psoriasis for example, it is likely that your arthritis is psoriatic arthritis. But, again, this is not a rule. We cannot confidently say that any patient who has psoriasis of the skin and complains of symptoms in their joints that they have to have psoriatic arthritis. They need to be assessed for that and as I mentioned the doctor will do that assessment and decide.

Number 6:

 Imaging: we can do some imaging studies. We don’t mean here plain X rays in particular. Plain X rays of course can show the different signs of both diseases but it takes such a long time for the findings of the disease to show on the plain X rays. Here we mean joint ultrasound and MRIs. We mostly order joint ultrasounds as they are cheaper and the information they offer us is more than enough still for making the differentiation.

Lastly, sometimes we cannot sort out. Yes, sometimes we cannot sort out if this is rheumatoid arthritis or psoriatic arthritis or a third inflammatory arthritis. Some patients will show us enough symptoms and signs to categorize them as belonging to the autoimmune arthritis family but not enough symptoms and signs to specifically give them a name of a disease in the autoimmune arthritis family.

---------------------------

This post was prepared and published by  Dr. Hatem Eleishi. Dr. Hatem Eleishi is a professor of rheumatology at Cairo university (Egypt) and is especially dedicated to supporting arthritis patients with online educational videos and articles about arthritis causes and treatment. He also runs a rheumatology clinic in Cairo and a center for www.tabibakom.com/en that, in addition to providing online rheumatology consultations, also provides online medical consultations in several different medical specialties by expert consultants from Egypt, Canada and the United States.

---------------------------

If you are interested in receiving the links of Dr. Hatem's videos to patients on your WhatsApp, kindly click here

---------------------------

To check the library of you tube videos of Dr. Hatem for patients, kindly click here

---------------------------

To watch the educational videos of Dr. Hatem on his you tube (Dr. Hatem Eleishi Arthritis channel), kindly click here