American Board of Internal Medicine (ABIM) Certification Practice Exam

What symptom combination strongly suggests the diagnosis of scleroderma?

1. Only skin induration

2. Pitting and heartburn

3. Joint pain and fever

4. Skin induration plus digital infarction

The correct answer is: Skin induration plus digital infarction

The combination of skin induration plus digital infarction strongly suggests the diagnosis of scleroderma. Scleroderma, or systemic sclerosis, is characterized by the pathological deposition of collagen that leads to skin thickening and hardening (induration). This symptom alone is common in various conditions, but when it is accompanied by digital infarction—where small areas of tissue (often fingers or toes) die due to reduced blood flow—it becomes particularly indicative of scleroderma. Digital infarctions in scleroderma occur due to vascular abnormalities and the involvement of the small blood vessels, which is a hallmark of the disease. The presence of both skin induration and digital infarction points towards the progression of vascular and connective tissue damage typical of scleroderma. In contrast, the other combinations do not exhibit the same strong correlation with scleroderma. For instance, only having skin induration lacks the specific vascular complication that digital infarction provides. Pitting and heartburn may suggest esophageal involvement seen in several conditions but is not specific to scleroderma. Joint pain and fever could be related to many inflammatory conditions and do not point specifically to scleroderma. Therefore, the specific combination of skin induration and