Summary about Disease
A recurring digital mucous cyst is a small, fluid-filled sac (cyst) that develops near the distal interphalangeal (DIP) joint (the joint closest to the fingertip) on the fingers or toes. It's often associated with underlying osteoarthritis in the joint. The cyst is filled with a gelatinous fluid that is similar to the fluid found in joints (synovial fluid). They tend to recur even after treatment.
Symptoms
A small, firm, smooth, and shiny bump near the DIP joint of a finger or toe.
The cyst is usually skin-colored or translucent.
It may be tender or painful, especially with pressure or movement.
Grooving or indentation of the nail plate may occur if the cyst presses on the nail matrix (where the nail grows from).
Leakage of clear, jelly-like fluid may occur if the cyst ruptures.
Pain or stiffness in the DIP joint.
Causes
Osteoarthritis: The most common cause is underlying osteoarthritis in the DIP joint. Bone spurs (osteophytes) associated with osteoarthritis can irritate the joint capsule, leading to cyst formation.
Trauma: Injury to the joint can sometimes trigger cyst development.
Degeneration: General wear and tear on the joint over time.
Unknown: In some cases, the exact cause is not known.
Medicine Used
Topical Corticosteroids: Applied to the cyst to reduce inflammation, but typically not very effective alone.
Needle Drainage (Aspiration): Fluid is drained from the cyst using a needle. This provides temporary relief but recurrence is common.
Corticosteroid Injection: Injecting a corticosteroid into the cyst after drainage may reduce inflammation and recurrence.
Hyaluronic Acid Injection: Injection of Hyaluronic acid may reduce inflammation and recurrence.
Surgical Excision: The cyst is surgically removed. This is often the most effective treatment, but carries a risk of complications.
Cryotherapy: Freezing the cyst with liquid nitrogen.
Laser Therapy: Using a laser to destroy the cyst.
Is Communicable
No, recurring digital mucous cysts are not communicable. They are not caused by an infection and cannot be spread to other people.
Precautions
Avoid picking or squeezing the cyst: This can increase the risk of infection.
Protect the affected area: Avoid activities that put pressure on the cyst or joint.
Keep the area clean and dry: If the cyst ruptures, clean the area with soap and water and cover it with a bandage.
Manage underlying osteoarthritis: Follow your doctor's recommendations for managing osteoarthritis, such as pain relievers, physical therapy, or joint injections.
Consider assistive devices: Use assistive devices such as splints or finger supports to protect the affected joint.
How long does an outbreak last?
The duration of a digital mucous cyst outbreak varies.
Untreated: A cyst may persist for weeks, months, or even years if left untreated. It may fluctuate in size and discomfort.
After drainage (aspiration): The cyst may refill within days to weeks.
After surgical excision: If the underlying cause (osteoarthritis) is not addressed, there is a chance of recurrence, even after surgery.
With other treatments: The duration of relief varies depending on the treatment method and individual response.
How is it diagnosed?
Physical Examination: A doctor can usually diagnose a digital mucous cyst based on its appearance and location.
Medical History: The doctor will ask about your medical history, including any history of osteoarthritis or trauma to the affected area.
X-rays: X-rays may be taken to assess the underlying joint and look for signs of osteoarthritis, such as bone spurs.
Aspiration: Fluid can be removed from the cyst with a needle to confirm the diagnosis and rule out other conditions. Fluid is typically clear and gelatinous.
Timeline of Symptoms
Initial Stage: A small, often painless bump appears near the DIP joint.
Progression: The cyst may gradually increase in size over time. Pain or tenderness may develop, especially with pressure or movement.
Nail Changes: If the cyst presses on the nail matrix, a groove or indentation may appear on the nail.
Rupture (Optional): The cyst may rupture spontaneously, releasing a clear, jelly-like fluid. This may temporarily relieve pressure and pain, but recurrence is common.
Chronic Stage: If left untreated, the cyst may persist for a long time, causing chronic pain, stiffness, and functional limitations.
Treatment and Recurrence: Symptoms may temporarily improve with treatment (aspiration, surgery, etc.), but the cyst often recurs, restarting the cycle.
Important Considerations
Underlying Osteoarthritis: It's crucial to address the underlying osteoarthritis, as it's the primary cause of recurring digital mucous cysts.
Recurrence: Recurrence is common, even after treatment. Multiple treatments may be required.
Infection Risk: Any procedure that involves puncturing the skin (aspiration, injection, surgery) carries a risk of infection.
Nail Deformity: Prolonged pressure on the nail matrix can lead to permanent nail deformity.
Functional Limitations: Pain and stiffness can limit hand or foot function, affecting daily activities.
Specialist Referral: If the cyst is large, painful, or causing significant functional limitations, or if initial treatments are ineffective, referral to a hand surgeon or dermatologist may be necessary.
Patient Expectations: Patients should be informed about the possibility of recurrence and the need for ongoing management of the underlying osteoarthritis.