What is Sausage Digit?

Dactylitis is a severe swelling of the fingers or toes that causes a sausage-like appearance in the digit and may be referred to as "sausage digit." Dactylitis can occur in many spondyloarthritis conditions, including ankylosing spondylitis (AS). The swelling may come and go, lasting for a period of time and then going away, although many people experience recurrent dactylitis. In addition to the sausage-like appearance, dactylitis can be very painful and can cause a marked reduction in the mobility of the affected fingers or toes.¹

What causes sausage digit?

The inflammatory response is the immune system's natural reaction when cells are stressed or damaged, or when there is a foreign invader (like a viral, fungal, or bacterial infection). This type of inflammation is usually acute and only lasts a short period of time.

In people with AS, there is chronic inflammation in the joints. Primarily with AS, the joints in the spine and the sacroiliac joints (those between the base of the spine and the pelvis) are affected, although peripheral joints (those in the arms or legs) can also have inflammation. The chronic inflammation wears away at the bone of the joints. As the body works to replace the lost bone, it can create too much bone in the joint, leading to a fusing of the joint. The entheses and ligaments may also become calcified, called syndesmophytes. Joint fusion immobilizes the joint, causing rigidity or limited mobility.³

The inflammation in dactylitis may be in the joints of the fingers or toes, the metacarpophalangeal joints in the fingers and the metatarsophalangeal joints in the toes. Inflammation can similarly occur in the attachment points of tendons and ligaments, called entheses. (Inflammation in the entheses is called enthesitis.) The swelling of dactylitis is also due to inflammation in the fluid-filled capsule (synovium) around the flexor tendon of the digit, called flexor tenosynovitis.¹

Who gets sausage digit?

Dactylitis can occur in people with spondyloarthritis, including psoriatic arthritis and AS. Dactylitis is more common in people with psoriatic arthritis than it is in people with AS.⁴

Dactylitis can also happen as a result of an infection.²

How is sausage digit assessed?

Dactylitis will be assessed by a doctor during a physical examination and symptom history. During the physical examination, the doctor will assess the tenderness of the affected joint. They may measure the size of the affected digit as compared to the unaffected side. The patient should be prepared to describe when the symptoms appeared and all their health conditions.^2,5

How is dactylitis treated?

Like other manifestations of AS, dactylitis may be treated with medications including^6,7:

• Non-steroidal anti-inflammatory drugs (NSAIDs), which can help relieve pain and inflammation
• Biologic medications, which may help slow or stop the progression of the disease by blocking key processes or compounds involved in the inflammatory response
• Corticosteroids, which may be used for short-term relief of inflammation
• Slow-acting anti-rheumatic drugs (SAARDs), which may help relieve pain and inflammation, especially in those who cannot take biologic medications