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Dr. Jennifer Pérez Mejia

Medical | Internal Medicine

Rheumatology Specialist at RHEUMAR Clinic in Puerto Vallarta Mexico treating Rheumatic diseases including Rheumatoid Arthritis, Osteoarthritis, Gout, Juvenile Arthritis and more.

What is Rheumatology?

Subspecialty of internal medicine that studies systemic and musculoskeletal autoimmune diseases such as rheumatoid arthritis, Lupus, gout, fibromyalgia, osteoarthritis, among others.




Osteoarthritis (OA) is the most common form of arthritis and is more common in older people. Some people call it degenerative joint disease or “wear and tear” arthritis. It occurs most frequently in the hands, hips, and knees.


  • Pain
  • Stiffness
  • Tenderness
  • Loss of flexibility
  • Grating sensation
  • Bone spurs
  • Swelling

A Doctor diagnoses OA  through a review of symptoms, physical examination, X-rays, and lab tests. A rheumatologist can help if there are any questions about the diagnosis.


Juvenile Idiopathic Arthritis

Arthritis in children is called Juvenile Idiopathic Arthritis (JIA). It is the most common type of arthritis in children under the age of 16.

Some children may experience symptoms for only a few months, while others have symptoms for many years.


  • Joint pain
  • Swelling / Stiffness
  • Fever / Rash
  • Loss of appetite
  • Fatigue

There are several different subtypes of juvenile idiopathic arthritis. Which type your child has depends on symptoms, the number of joints affected, and if a fever and rashes are prominent features.

Take your child to the doctor if he or she has joint pain, swelling or stiffness for more than a week — especially if he or she also has a fever.


Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is an autoimmune and inflammatory disease, which means that your immune system attacks healthy cells in your body by mistake, causing inflammation (painful swelling) in the affected parts of the body.


  • Tender, warm, swollen joints
  • Joint stiffness that is usually worse in the mornings and after inactivity
  • Fatigue, fever and loss of appetite

Unlike the wear-and-tear damage of Osteoarthritis, Rheumatoid arthritis affects the lining of your joints, causing a painful swelling that can eventually result in bone erosion and joint deformity. It can also affect other parts of the body and cause problems in organs such as the lungs, heart, and eyes.

Make an appointment with your Doctor if you have persistent discomfort and swelling in your joints.

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When should you see a rheumatologist?

Systemic autoimmune conditions can affect organs and areas throughout your body, leading to a variety of symptoms. The common symptoms include:


  • Pain, stiffness or swelling in more than one joint
  • Fatigue
  • Generalized weakness
  • Skin rashes or lesions
  • Hair loss

Most Common Diseases Treated

  • Juvenile idiopathic arthritis
  • Chronic gout
  • Vasculitis
  • Rheumatoid arthritis
  • Osteoarthritis
  • Sjogren’s syndrome
  • Fibromyalgia
  • Multiple Sclerosis (MS)
  • Lupus

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There are more than 200 Rheumatic diseases, including rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, lupus and fibromyalgia.


  • Midwife surgeon, University of Guadalajara 2010
  • Internal medicine, University of Guadalajara 2015
  • Rheumatology, University of Guadalajara 2017
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If you are not currently in Mexico but would like an online consultation, fill out the form below to set up a meeting. Pick a preferred date and time to arrange a visit.



Av. Francisco Villa 1389 C. Grupo Diagnosti-k, Fluvial Vallarta, Puerto Vallarta, Mexico


Monday – Friday (10 am – 2 pm) (4 pm – 8 pm)

What Does a Rheumatologist Do?

Doctors who specialize in rheumatology study conditions that affect the connective tissues.  Because some connective tissue problems and autoimmune diseases affect the entire body, rheumatologists are trained to look at the whole person.

Rheumatologists have a lot of direct contact with their patients. They often provide long-term follow-up care.

What is an Autoimmune Disease?

Autoimmune diseases result when your immune system is overactive, causing it to attack and damage your body’s own tissues.

With autoimmune disorders, your immune system can’t tell the difference between invaders and healthy cells.

They can affect your skin, eyes, and internal organs, in addition to joints, muscles, and bones.

What are the causes of Autoimmune Diseases?

The exact causes of autoimmune diseases are unknown, but scientists have some theories on what triggers them:

  • Certain medications | Genetics | Infections

Certain risk factors raise your chances of getting an autoimmune disorder. Some common ones include:

  • Smoking
  • Exposure to toxins
  • Female gender (78% of people with an autoimmune disease are women
  • Obesity

Comparing Rheumatoid Arthritis and Osteoarthritis

Rheumatoid arthritis and osteoarthritis are different types of arthritis. They share some similar characteristics, but each has different symptoms and requires different treatment. So an accurate diagnosis is important.

Osteoarthritis is the most common form of arthritis. Rheumatoid arthritis affects about one-tenth as many people as osteoarthritis. The main difference between osteoarthritis and rheumatoid arthritis is the cause behind the joint symptoms. Osteoarthritis is caused by mechanical wear and tear on joints. Rheumatoid arthritis is an autoimmune disease in which the body’s own immune system attacks the body’s joints.

  • Osteoarthritis is usually called arthritis. Many people get this type of arthritis as they age. It happens when the cartilage that cushions your joints—like your knees and hips—gradually breaks down. Then the bones rub against each other. This causes damage and pain. There are many treatments that can help with the pain and make it easier to move.
  • Rheumatoid arthritis is a type of arthritis in which your body’s immune system attacks healthy tissue in your joints. This makes the joints swollen, stiff, and painful. Over time, it may destroy the joint tissues and make it hard for you to walk and use your hands. Medicine may help control rheumatoid arthritis or keep it from getting worse.

Characteristics of rheumatoid arthritis and osteoarthritis

  • Characteristic – Age at which the condition starts
    • Rheumatoid arthritis – It may begin any time in life.
    • Osteoarthritis – It usually begins later in life.
  • Characteristic – Speed of onset
    • Rheumatoid arthritis – Relatively rapid, over weeks to months
    • Osteoarthritis – Slow, over years
  • Characteristic – Joint symptoms
    • Rheumatoid arthritis – Joints are painful, swollen, and stiff.
    • Osteoarthritis – Joints ache and may be tender but have little or no swelling.
  • Characteristic – Pattern of joints that are affected
    • Rheumatoid arthritis – It often affects small and large joints on both sides of the body (symmetrical), such as both hands, both wrists or elbows, or the balls of both feet.
    • Osteoarthritis – Symptoms often begin on one side of the body and may spread to the other side. Symptoms begin gradually and are often limited to one set of joints, usually the finger joints closest to the fingernails or the thumbs, large weight-bearing joints (hips, knees), or the spine.
  • Characteristic – Duration of morning stiffness
    • Rheumatoid arthritis – Morning stiffness usually lasts longer than 1 hour.
    • Osteoarthritis – Morning stiffness usually lasts less than 1 hour. Stiffness returns at the end of the day or after periods of activity.
  • Characteristic – Presence of symptoms affecting the whole body (systemic)
    • Rheumatoid arthritis – Frequent fatigue and a general feeling of being ill are present.
    • Osteoarthritis – Whole-body symptoms are not present.