Plant Thorn Synovitis An Interesting Type Of Arthritis}

Submitted by: Nathan Wei

An interesting topic that very few people- even doctors- dont know about , is a condition called plant thorn synovitis.

This problem occurs when a thorn from a plant enters a joint by puncturing it. This can happen during the course of gardening, trimming plants, or even while walking through dense brush where one uses their hands to push away branches.

Once the thorn punctures the joint- usually a joint in the hand- it leaves some plant matter inside the joint. This sets up an acute localized inflammatory response within the synovium- the lining of the joint.

Symptoms include joint swelling, redness, heat, and pain, accompanied by stiffness and reduced range of motion. The inflammatory reaction inside the joint is called synovitis.

Thorny plants that are most often associated with this problem are rose bushes. However, there are other thorny plants that can do this. These include: palm trees, black-thorn shrubs, cacti, bougainvillea, yucca, pyracantha, plum trees, and mesquite trees (

While small hand and finger joints are most often affected, other joints can also be involved.

Symptoms of plant thorn synovitis may not develop for several days or even weeks after the puncture. The patient may not even recall having a puncture because the actual puncture may not have been that painful.

Plant thorn arthritis may be suspected if a patient comes in with a single joint that is inflamed. A careful history may produce the fact that they had been punctured by a plant thorn. Even if the plant thorn was removed by the patient, microscopic amounts of plant matter are left inside the joint and this is what causes the inflammatory response to develop.

The initial procedure is to insert a needle into the joint and draw out fluid to make sure that some other type of infection or other type of inflammatory process such as gout is not responsible for the problem.

Once this is done, then a patient can be sent for x-rays or MRI scanning to better delineate the process. Diagnostic ultrasound can also be of value.

Unfortunately, though, even these sophisticated imaging procedures may not detect the minute plant particles and the patient may need to undergo surgery.

The surgeon will open the joint and remove the entire area of inflamed synovium (joint lining).

Examination of the synovial tissue by a pathologist will show the microscopic pieces of thorny material. In addition, the pathologist will be able to identify what is called a granulomatous reaction. This is a typical biologic response that occurs in body tissue when exposed to a chronic irritant such as plant matter.

Another danger that can occur as a result of a thorny puncture is a septic or infected joint. This is a medical/surgical emergency since untreated infection will cause joint destruction but can also lead to systemic sepsis. Antibiotics and surgical debridement are generally required.

The long term prognosis for plant thorn synovitis is a good one if the diagnosis is suspected and early intervention is instituted.

Prevention is difficult but if plant enthusiasts at least are aware of this potential problem, it makes the diagnosis easier should it occur.

About the Author: Nathan Wei, MD FACP FACR is a board-certified rheumatologist and nationally known arthritis authority and expert. For more info:

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