Mauro Keiserman, MD. Rheumatology Specialist by the Brazilian Society of Rheumatology. Head Professor of Rheumatology at the Catholic University School of Medicine (PUC-RS).

What is it?

Rheumatoid arthritis (RA) is a chronic disease of unknown cause. Its main characteristic is a persistent joint inflammation, but there are cases in which other organs are involved.

What’s its frequency

It’s a common disease, and its prevalence may reach up to 1.5% of the population in some regions. It’s more frequently found in women and usually starts between ages 30 and 50, also attacking men and children. For the disease to develop, some combinations of genetic defects and the presence of one or more external stimuli are needed, which avoids a large incidence in the families of rheumatoid arthritis patients.

How does it develop?

There is a genetic predisposition, and some genes have been identified. The cause of RA remains unknown, and several different stimuli are thought to exist, which, when in contact with individuals carrying defects of a genetic origin in the immune system, may trigger an inflammatory response. The persistence of stimuli or the inability of the immune system to control inflammation lead the disease to become chronic. The synovial membrane proliferates and releases enzymes locally produced by cells. Both the invasion of the synovial membrane and the action of enzymes cause the destruction of joint structures (cartilage and adjacent bone) and juxta-articular structures (tendons and ligaments).

What does one experience?

The most frequent form of onset is symmetrical arthritis (e.g.: the two wrists, the fingers of both hands) and additive arthritis (the first joints involved keep on suffering from the condition, and others are added). Usually, its onset is slow and little aggressive, being located in small joints of the hands at first.

There are acute and rapidly restraining forms. Less commonly, it starts in large joints or in an asymmetrical fashion; it may remain at this, or progress into classic symmetric polyarthritis. Every peripheral joint can be involved, and the damage to the cervical column may be very severe. Only in very aggressive RA there is arthritis in the distal interphalangeal joints of the fingers, with late onset. Temporomandibular arthritis is common.

A feature of RA is morning stiffness. After a night of sleep, patients wake up experiencing significant difficulty moving their joints, a state that remains for 1 hour. In more severe cases, morning stiffness resolves only partially, with pain and restriction of motions lasting on a permanent basis. Some patients complain about feeling unwell, fatigue, and muscle pain, which can accompany or precede arthritis. Morning stiffness and fatigue by the end of the afternoon are used to evaluate the disease activity.

Destructive articular changes are variable in the same patient and among the population with RA. There are quite benign cases and cases with discreet or absent changes, as well as others in which deformities are established progressively and become extremely severe, even with adequate treatment.

Some patients with typical RA report that over months or years they experienced temporary outbreaks of arthritis in several or a few joints before the disease becomes chronic.

The most common clinical course is characterized by partial alleviation of the inflammatory activity. Fewer times, there’s inactivity for varying periods of months or years. In more severe cases, the disease evolves progressively, leading to severe articular disability over time.

Extra-articular clinical manifestations:

Rheumatoid nodules

These are nodules located under the skin, mainly in supporting areas such as the elbows. Generally, they appear in more severe cases. They seldom occur in the lungs, heart, eyes, or other organs. (figure beside)

Ocular involvement

The most frequent change is the inflammation of lacrimal glands (Sjögren’s Syndrome).

Consequently, there’s a reduction in tear production. The eyes become irritated, with a sensation of sand in them. When not properly treated, the cornea is subject to erosion and infection.

Other eye structures may also be inflamed. The most serious is scleritis; when scleritis is severe, eyeball perforation may occur.

Muscle manifestations

Muscle inflammation rarely occurs. Conversely, joint inflammation and lack of its use are mandatory causes for muscle hypotrophy. Drugs habitually used in RA, such as corticoids and antimalarials may be the cause of muscle weakness, and, sometimes, it’s hard to discern between manifestations by the disease and those by the medications. In these cases, if the patient improves his/her strength by performing exercises, drugs aren’t the cause.

Nervous system

It’s common to observe the involvement of peripheral nerve roots. When only sensory nerve roots are attacked, the symptom is a sensation of formication or burning, as though the patient were wearing gloves or boots, and the prognosis is good, unlike less common cases of motor neuropathy.

Also common are compression neuropathies due to the inflammation and proliferation of articular tissue. The most common symptom is formication in the thumb, index and middle fingers because of compression of the median nerve at the level of the wrist.

Loosening or destruction of ligaments in the cervical column allow the 1st vertebra to slide, which can compress the spinal cord. The outcome is sensory and motor disorders in the upper and lower limbs. Greater displacements of the vertebra may lead to paralysis and even respiratory arrest and death.


Mild anemia is related to RA activity. When hemoglobin is below 10 g/ml or the hematocrit is below 30 with the disease under control, we must seek blood loss through the stomach due to the continued use of anti-inflammatory agents.

The association of RA with an increase in the spleen’s size, anemia, decline in white blood cells, and other manifestations of the disease is called Felty’s syndrome.


The clinical manifestation of vasculitis depends upon lesion intensity, location and size of the vessel.

Inflammations around the fingernails are not rare and have a good course.

Patients with severe RA can present extensive areas of skin vasculitis causing ulcers hard to manage.

This is to be continued in Inflammatory Activity Evaluation…

Questions you can ask your doctor

Does this disease have a cure?

What’s the purpose of the treatment?

Is it a single treatment or must it be repeated?

Is there any interference with the other medications I’m taking?

What are the side effects? Should I undergo follow-up exams?

Are there problems with obesity and diet?

What’s the importance of exercises and rest?

What health-care measures should I take in my daily, professional and leisure activities?