Plant Thorn Arthritis (Plant Thorn Synovitis or Thorn Arthritis)

  • Medical Author:
    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

  • Medical Editor: Catherine Burt Driver, MD
    Catherine Burt Driver, MD

    Catherine Burt Driver, MD

    Catherine Burt Driver, MD, is board certified in internal medicine and rheumatology by the American Board of Internal Medicine. Dr. Driver is a member of the American College of Rheumatology. She currently is in active practice in the field of rheumatology in Mission Viejo, Calif., where she is a partner in Mission Internal Medical Group.

Symptoms of Rheumatoid Arthritis

Plant thorn arthritis facts

  • Plant thorn arthritis is a noninfectious inflammation of a joint as a result of a thorn puncturing the joint and leaving residual plant matter lodged within the joint.
  • Plant thorn arthritis typically affects only a single joint -- the joint that was pierced by the plant thorn.
  • Plant thorn arthritis causes the involved joint to be swollen, slightly reddish, stiff, and painful. The joint loses its full range of motion and is often tender.
  • The symptoms of plant thorn arthritis may occur long after the thorn is removed from the affected joint.
  • The diagnosis of plant thorn arthritis requires either detection of a piece of thorn within the joint by radiology testing or surgical removal of the thorn fragments and identification of the fragments microscopically in the laboratory.
  • Synovectomy is the surgical procedure that is used to cure plant thorn arthritis.

What is plant thorn arthritis?

Plant thorn arthritis is a noninfectious inflammation of a joint as a result of a thorn puncturing the joint and leaving residual plant matter lodged within the joint. The plant thorn fragments cause a localized inflammation reaction in the joint lining tissue that leads to swelling, stiffness, loss of range of motion, and pain. The joint lining tissue is called the synovium. Inflammation of this tissue is medically referred to as synovitis. Plant thorn arthritis is also called plant thorn synovitis.

What plants cause plant thorn arthritis?

The plants that commonly cause plant thorn arthritis are those that produce thorns. These plants include palm trees, roses, black-thorn shrubs, cacti, bougainvillea, yucca, pyracantha, plum trees, and mesquite trees. Exposure to these plants is the greatest risk factor for plant thorn arthritis.

Doctor Gets Plant Thorn Arthritis

One patient's story

In a reasonable attempt to better the lives of my daughter, Cara, and son-in-law, Jim, as well as enjoy their company during a concentrated effort, I assisted them in landscaping one fine weekend day.

Jim was industriously off at the store purchasing cement blocks, and I was in a hurry to get the pruning completed so as not slow the construction of a block retaining wall upon his return. I was wearing gloves that had extra padding over the knuckles...

What are risk factors for plant thorn arthritis?

Risk factors for plant thorn arthritis include gardening, especially without gloves, and exposure to thorn-bearing plants, including palm trees, roses, black-thorn shrubs, cacti, bougainvillea, yucca, pyracantha, plum trees, and mesquite trees.

What joints are typically involved in plant thorn arthritis?

Plant thorn arthritis typically affects only a single joint -- the joint that was pierced by the plant thorn. The most common joints affected by plant thorn arthritis are those that can be exposed to being stabbed by falling into or brushing up against plants with thorns. Joints that are commonly affected by plant thorn synovitis include the small joints of the hands (metacarpophalangeal joints, proximal interphalangeal joints), feet, elbows, knees, and ankles.

What are plant thorn arthritis symptoms and signs?

Plant thorn arthritis causes the involved joint to be

  • swollen,
  • slightly reddish,
  • stiff, and
  • painful.

The joint loses its full range of motion and is often tender. These symptoms may be noticed only many days after the initial thorn puncture. It is not uncommon for the person affected by plant thorn arthritis to remove the thorn immediately after the puncture and then develop the arthritis many days or weeks later and not even recall that the joint had been punctured previously! This is because the original thorn has actually left behind small fragments of thorn vegetable matter that gradually cause the inflammation of plant thorn arthritis. This form of single joint arthritis (monoarthritis) then becomes chronic until appropriately treated.

What specialties of doctors treat plant thorn arthritis?

Plant thorn arthritis requires operative intervention. Doctors who perform operative treatments include orthopedic surgeons and plastic surgeons.

How is plant thorn arthritis diagnosed?

Plant thorn arthritis is suspected in a patient who presents with a single joint that is inflamed after it has been punctured by a plant thorn. This is true even if the patient recalls removing the thorn, as described above, because the thorn can leave behind tiny fragments of thorn matter that leads to the chronic inflammation of plant thorn arthritis.

Removal of joint fluid (joint aspiration) is performed to rule out bacterial or fungal infection of the joint.

Ultimately, the diagnosis of plant thorn arthritis requires either detection of a piece of thorn within the joint by radiology testing or surgical removal of the thorn fragments and identification of the fragments microscopically in the laboratory. Sometimes tiny pieces of thorns can be visualized using magnetic resonance imaging (MRI scanning), high-resolution computerized tomography (HR-CAT scanning), or ultrasound imaging. Often, however, the residual thorn fragments are too small to be seen with these methods and are detected only when identified in tissue that is surgically removed from the joint.

The affected joint lining tissue (synovium) is examined in the pathology department using microscopes. The tissue forms a characteristic reaction, called a granulomatous reaction, within the synovium (granulomatous synovitis). The microscopic thorn fragments are easily identified using a polarized light microscope as they appear brilliantly shiny (birefringent) to the examining pathologist.

Pathology photo showing multinucleated giant cell granulomatous reaction (triangle point), synovial hyperplasia, fibrosis, and adjacent foreign vegetable matter (arrow with thorn fragments) with H&E stain.
Pathology photo showing multinucleated giant cell granulomatous reaction (triangle point), synovial hyperplasia, fibrosis, and adjacent foreign vegetable matter (arrow with thorn fragments) with hematoxylin and eosin stain (H&E stain). Kindly provided by Xiaohui (Sheila) Zhao, MD, PhD, of the Department of Pathology and Laboratory Medicine, University of California, Irvine Medical Center.
Pathology photo showing thorn material (blue and yellow birefringent material) visualized under polarized light microscopy.
Pathology photo showing thorn material (blue and yellow birefringent material) visualized under polarized light microscopy. Kindly provided by Xiaohui (Sheila) Zhao, MD, PhD, of Department of Pathology and Laboratory Medicine, University of California, Irvine Medical Center.

What is the treatment for plant thorn arthritis?

It is important to recognize that puncturing a joint with a foreign material, such as a plant thorn, can lead to bacterial infection (septic arthritis) or fungal infection (fungal arthritis) of the joint. This possibility can be excluded by removing joint fluid and culturing the fluid in the laboratory. While plant thorn arthritis is technically noninfectious, these two forms of infectious arthritis can occur from plant thorn puncture of a joint, with or without true plant thorn arthritis. These forms of arthritis require urgent antibiotic treatment.

For plant thorn arthritis, anti-inflammatory medications may quiet some of the inflammation. However, chronic arthritis eventually develops even long after the plant thorn injury because of the thorn fragments remaining in the joint. This arthritis persists until the fragments are removed with a surgical operation. Without surgical resection of the plant fragments, joint inflammation persists and permanent joint destruction can occur. There is no specific medication or home remedy for plant thorn arthritis.

The surgical operation that can cure plant thorn arthritis is called a synovectomy with joint lavage (joint washout cleaning). During a synovectomy, the surgeon will remove the affected and surrounding joint lining tissue (synovium) to be certain that microscopic joint fragments within the joint and its lining are eliminated from the body.

Intraoperative photos of the author's right third metacarpophalangeal joint
With permission, these are intraoperative photos of the author's right third metacarpophalangeal joint exposing inflamed joint lining tissue (synovium) from which a 1 mm thorn tip from the common palm tree Phoenix roebelenii was surgically resected. Kindly provided by Gabriel Trainer, MD, and Neil Jones, MD, orthopedic hand surgery, University of California, Irvine Medical Center.
Photos of joint lining tissue resected from author's right third metacarpophalangeal joint
With permission, photos of joint lining tissue (yellowish synovium) resected from author's right third metacarpophalangeal joint after thorn puncture with 1 mm thorn tip (dark dot on thorn covered with joint lining tissue) from the common palm tree Phoenix roebelenii. Surgical resection of the inflamed tissue (synovitis), as well as all thorn fragments, is the key to curing plant thorn arthritis (plant thorn synovitis). Kindly provided by Gabriel Trainer, MD, and Neil Jones, MD, orthopedic hand surgery, University of California, Irvine Medical Center.

What is the prognosis of plant thorn arthritis?

Once a synovectomy for plant thorn arthritis has been performed, the joint tends to heal well without residual problems. The sooner the synovectomy is performed, the better the outcome as chronic joint inflammation can risk damage to cartilage of the joint. Physical therapy rehabilitation exercises can be helpful to restore normal joint function.

Is it possible to prevent plant thorn arthritis?

Plant thorn arthritis can be prevented by avoiding exposure to the thorns of plants. It can help to wear protective clothing, gloves, etc., as well as being cautious when near or working with thorny plants.

REFERENCES:

Stevens, K.J., et. al. "Imaging of Plant-Thorn Synovitis." Skeletal Radiol 29 (2000): 605-608.

Sugarman, M., D.G. Stobie, F.P. Quismorio, R. Terry, and V. Hanson. "Plant Thorn Synovitis." Arthritis Rheum 20.5 June 1977: 1125-1128.

Last Editorial Review: 8/2/2016

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Reviewed on 8/2/2016
References
REFERENCES:

Stevens, K.J., et. al. "Imaging of Plant-Thorn Synovitis." Skeletal Radiol 29 (2000): 605-608.

Sugarman, M., D.G. Stobie, F.P. Quismorio, R. Terry, and V. Hanson. "Plant Thorn Synovitis." Arthritis Rheum 20.5 June 1977: 1125-1128.

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