Fungal Arthritis

Fungal arthritis is inflammation of a joint by a fungus microorganism that has invaded the body and is growing in the normally sterile joint. Fungal infection of a joint is a serious condition that can lead to permanent damage to the joint with loss of function.

Fungal arthritis is also referred to as mycotic arthritis.

Fungal arthritis is usually caused by the fungus traveling through the bloodstream to reside in the joint. This manner of infection through the blood is referred to as the hematogenous spread.

Alternatively, if the medication that is contaminated by fungus is directly injected into the joint, fungal arthritis can result. This manner of infection by directly injecting the fungus into the joint is referred to as exogenous inoculation. Rarely, fungal infection can result from a contaminated prosthesis used in joint replacement surgery.

Fungal organisms that can cause fungal arthritis include Candida, Aspergillus, and Exserohilum species.

Fungal arthritis in people with normal immune systems is rare. One risk for developing fungal arthritis in such people is the accidental injection of medications that are contaminated with fungus microbes in the vials used. This, in fact, was the situation when contaminated vials of medications produced by a compounding pharmacy (New England Compounding Center) caused a multistate outbreak of rare fungal meningitis and fungal arthritis in September 2012.

People with abnormally suppressed immune systems are at risk for fungal infections, including fungal arthritis. This includes people with severely low white blood counts (neutropenia), HIV infection, injection drug abusers, and those taking chronic cortisone medication.

Symptoms of fungal arthritis include the following:

• Pain
• Heat
• Swelling
• Warmth
• Redness
• Loss of range of motion of the affected joint

The most common joint to develop fungal arthritis is the knee joint. Fever may or may not be present.

Symptoms of fungal arthritis typically become manifest weeks to months after the initial infection of the joint. Ultimately, fungal arthritis can potentially permanently damage the involved joint.

Fungal arthritis is considered when a patient whose immune system is compromised develops inflammation of a joint.

• Blood tests can include testing the blood for the white blood count, inflammation markers (sedimentation rate, or ESR, and C-reactive protein, or CRP), and cultures of the blood.
• Plain X-ray images, CAT scanning, and/or MRI scanning can be used to determine the character and extent of joint damage.

Ultimately, joint fluid is aspirated from the joint with a needle and syringe and this fluid is analyzed in the laboratory to culture the precise fungal organism and establish the diagnosis.

Fungal arthritis is a medical emergency. It is treated by infectious-disease specialists together with orthopedic surgeons.

Fungal arthritis is treated with antibiotics that are directed against the precise fungal microbe that is causing the joint infection. Examples of antibiotics for fungal arthritis include:

• amphotericin B
• fluconazole (Diflucan)
• caspofungin (Cancidas)

Adequate drainage of the infected joint is an additional essential part of the treatment. This generally requires orthopedic surgical procedures.

There are no home remedies for fungal arthritis.

The outlook for fungal arthritis is directly related to how much damage occurs to the cartilage and bone of the joint. Earlier treatment leads to optimal outcomes.

Fungal arthritis can be prevented by minimizing the risks of immune suppression and avoiding intravenous drug abuse. Fungal arthritis can also be prevented by active sterilization measures by companies producing injectable medications.