Introduction: Who Should Undergo Diagnostics

People living with systemic sclerosis (also called scleroderma) should be particularly aware of the possibility of developing digital ulcers, especially if they experience Raynaud’s phenomenon. Raynaud’s phenomenon is a condition where the blood vessels in the fingers and toes narrow dramatically in response to cold or stress, causing the digits to change color—first white, then blue, and finally red. More than 95% of people with scleroderma experience Raynaud’s phenomenon, and approximately 30% to 50% of these individuals will develop digital ulcers at some point during their disease journey.^[2][7]

If you have been diagnosed with scleroderma and notice any areas of skin breakdown on your fingertips, over your knuckles, or at other pressure points on your hands, you should seek medical evaluation promptly. Early diagnosis and intervention can help prevent these wounds from worsening and reduce the risk of serious complications such as infection or tissue death. Those with diffuse scleroderma, younger age at disease onset, or positive anti-Scl-70 antibodies are at higher risk for developing digital ulcers and should be monitored more closely.^[7]

Anyone experiencing severe or worsening Raynaud’s attacks—particularly if fingers turn blue and become painful—should also undergo evaluation. This secondary form of Raynaud’s is different from primary Raynaud’s because the blood vessels do not return to their normal size between attacks. Over time, these vessels become progressively smaller and may even disappear entirely, leading to inadequate oxygen and nutrient supply to the skin.^[10] When the skin is starved of blood, it can crack, break down, and form ulcers that are difficult to heal.

Diagnostic Methods for Identifying Digital Ulcers

Diagnosing digital ulcers in scleroderma begins with a thorough clinical examination by a healthcare provider, typically a rheumatologist or a specialist familiar with connective tissue diseases. A digital ulcer is formally defined as an area with a visually discernible depth showing loss of continuity of the skin’s outer layers—specifically, both the dermis (the deeper layer of skin) and the epidermis (the outer layer of skin). These wounds have well-demarcated borders and may appear as open sores or may be covered by dead tissue or a scab.^[2][8]

During the physical examination, the doctor will carefully inspect all areas of your hands and fingers, paying particular attention to the fingertips where blood supply is most limited. Digital ulcers most commonly appear on the fingertips as a direct result of inadequate blood flow. However, ulcers can also develop over bony prominences such as the knuckles or joints, where repeated minor trauma and tight skin contribute to tissue breakdown.^[2][8]

The physician will assess the severity of the ulcers by noting their number, size, and depth. Severity may be classified as mild (one to five ulcers), moderate (six to ten ulcers), or severe (more than ten ulcers).^[7] The doctor will also look for signs of infection, such as redness, warmth, swelling, pus drainage, or an unpleasant odor. Infection is a significant concern because digital ulcers can become infected not only at the skin surface but also in the underlying bone, a condition known as osteitis or osteomyelitis.^[4]

To understand the underlying vascular problems contributing to ulcer formation, doctors may order specialized tests to evaluate blood flow in the hands. While the sources provided do not detail specific imaging or blood flow studies used routinely for digital ulcer diagnosis, clinical assessment of Raynaud’s phenomenon is integral to understanding ulcer risk. The doctor will ask about color changes in your fingers, whether your fingers become painful or numb with cold exposure, and whether you have noticed any progressive difficulty with hand function.

Laboratory blood tests may also be performed to identify antibodies associated with scleroderma, such as anti-Scl-70 antibodies, which are more commonly found in patients who develop digital ulcers.^[7] Determining the subtype of scleroderma—whether diffuse cutaneous or limited cutaneous—can also provide important prognostic information, as those with diffuse disease are at higher risk for ulcer development.^[7]

It is important to distinguish digital ulcers from other types of skin lesions that can occur in scleroderma. For example, calcinosis—deposits of calcium under the skin—can sometimes break through the skin surface and be mistaken for ulcers. Areas of trauma-related wounds or other skin conditions should also be differentiated from true ischemic digital ulcers caused by poor blood circulation.^[4]

Diagnostics for Clinical Trial Qualification

When patients with scleroderma-associated digital ulcers are being considered for enrollment in clinical trials, specific diagnostic criteria and assessment methods are used to ensure that participants meet the study requirements. These criteria help researchers evaluate whether new therapies are effective at healing existing ulcers or preventing new ones from forming.

Clinical trials typically require a confirmed diagnosis of systemic sclerosis according to established classification criteria, along with documented evidence of active digital ulcers at the time of enrollment. The definition of a digital ulcer used in trials is usually consistent with the clinical definition: a denuded area of tissue with well-demarcated borders involving loss of both the dermis and epidermis.^[2][8] Some trials may specify that ulcers must be located on the fingertips (ischemic ulcers) rather than over bony protuberances (trauma-related ulcers), as these two types may have different underlying causes and responses to treatment.^[2]

To qualify for clinical trials, patients may need to have a certain minimum number of active ulcers, or a history of recurrent ulcers over a defined period. Researchers often collect baseline data on the number, size, and location of ulcers using standardized wound assessment techniques. Photographic documentation of the ulcers may be obtained to allow objective comparison of ulcer healing over time. Patients may also be asked to rate their pain levels using standardized pain scales, and to complete questionnaires assessing hand function and quality of life.

Blood tests confirming the presence of scleroderma-specific antibodies may be required for trial eligibility. Patients with certain antibody profiles, such as anti-Scl-70, may be preferentially enrolled in studies focused on more severe vascular manifestations.^[7] Conversely, some trials may exclude patients with very severe disease, such as those with tissue death (necrosis) or gangrene requiring amputation.

Participants in clinical trials may also undergo additional tests to exclude other conditions that could interfere with the study results. For example, tests may be conducted to rule out significant infections at the ulcer sites, as active infection could complicate the interpretation of healing outcomes. Blood flow studies or imaging of the blood vessels in the hands might be performed to better characterize the extent of vascular damage, although specific details of these tests are not provided in the available sources.

Regular monitoring during the trial is essential. Patients typically attend frequent follow-up visits where the number of new ulcers, the healing progress of existing ulcers, and any complications are carefully documented. Standardized assessment tools help ensure that results are comparable across different study sites and patient populations. The ultimate goal is to determine whether the intervention being tested can improve ulcer healing, reduce the frequency of new ulcer formation, and enhance patients’ overall hand function and quality of life.