Sclerodactyly is a hardening of the skin of the hand that causes the fingers to curl inward and take on a claw-like shape. It is brought on by a condition called systemic scleroderma, or systemic sclerosis.

Systemic scleroderma often affects the hands, causing a tightening or hardening of the skin. But not everyone with scleroderma symptoms in the hands will get sclerodactyly.

Scleroderma is a form of arthritis. It is a rare disease. Fewer than a half million people in the United States are affected, and only some of these get sclerodactyly.

As the scleroderma of the hand progresses, your fingers can become so swollen that it’s hard to bend them.

In some cases, the skin may then thicken and become hard.

If it reaches the point that the hand becomes stiff like a claw, and the fingers immovable, it is then sclerodactyly.

There is usually also a wasting away of the underlying soft tissues.

Scleroderma is considered an autoimmune disease. Your immune system mistakes your own tissue for a foreign body and attacks it.

Your cells respond to the mistaken attack by over-producing a protein called collagen. Collagen is found in healthy skin, and makes it both supple and firm. But when too much collagen is produced, your skin can get hard and leathery.

There is some evidence that scleroderma, the cause of sclerodactyly, may be hereditary. Exposure to some pesticides, epoxy resins, or solvents may trigger scleroderma in certain people.

One of the early signs of scleroderma is extreme sensitivity to cold in the fingers or toes.

Your fingers may feel numb or painful. This can also be brought on by emotional stress.

As scleroderma progresses, the fingers and toes may swell and appear puffy.

The initial phase of scleroderma in the hands may be intermittent:

  • It may last for weeks, months, or years.
  • It is often worse in the morning.
  • Over time, the skin may thicken and then harden.
  • The skin on your hands can become so tight that there’s nothing there to pinch.

In some people, the fingers begin to harden and curl inward. The scleroderma symptoms in the hands only rarely progress to the condition of sclerodactyly. When this happens, the collagen fibers in the skin stiffen, the fingers can’t be moved, and the hand becomes stiff like a claw.

It’s very important to have treatment in the initial stages before the hands have hardened.

Treatment options for sclerodactyly include physical and occupational therapy, ultraviolet light, and surgery.

Physical therapy

Physical therapists can direct you in hand-stretching exercises that may bring relief from the early symptoms. The same hand exercises used for arthritis can be of help for some.

Hot wax machines can be used to warm the hands and help reduce pain.

Specialized hand therapists are trained to form casts for your hands to wear during the day and at night. These will allow you to carry out your regular activities. The cases are shaped so that if your hands harden, they will take a shape most useful for your everyday needs.

Ultraviolet (UV) light therapy

UVtherapy is a fairly new treatment prescribed by some doctors for sclerodactyly.

The hands are exposed to ultraviolet A1 (UVA1). This is a portion of the light spectrum that is contained in sunlight. UVA1 light produces only this part of the light spectrum.

UVA1 light is thought to help decompose the hardened collagen proteins under your skin tissue. The light penetrates into the middle layer of the skin where it acts on a variety of different types of cells.

One of its actions is to affect the cells known as fibroblasts that make collagen. The UVA1 can cause these cells to produce substances that will break down the excess collagen that is hardening the skin.

People with intolerance to sunlight or a history of skin cancers shouldn’t have UVA1 therapy.


Surgery is an option for people with sclerodactyly and systemic scleroderma affecting the hand. It won’t make the condition go away, but can provide pain relief. Surgery can also reposition your fingers to make the hand more useful.

Although there is still no cure, treatments for sclerodactyly have improved in the last 30 years. It’s most important to seek early treatment and physical therapy before the claw-like condition sets in.

Ultraviolet light treatment (phototherapy) has shown success for some people with sclerodactyly. But the results are mixed.

Your doctor may be able to help you find local support groups. Talking to others with the same condition can help.