A 27-year-old white man, an active-duty soldier who previously had been healthy, presented with a 5-month history of progressively worsening swelling, pain and, eventually, skin hardening in both legs and then arms. Associated symptoms included myalgia, fever, and fatigue. There was no clear toxin exposure or change in diet or medications. The patient, who was very physically active, engaged in strenuous daily activities.
On presentation, the patient was afebrile. The physical examination was notable for mild wrist contractures without synovitis. Taut and woody indurated skin was seen on the bilateral upper and lower extremities but spared the fingers, chest, feet, back, face, and neck. This classic finding is shown in the photograph (left). What term is used to describe it?
Laboratory studies were remarkable for peripheral eosinophilia (eosinophils up to 28%), mild elevation of inflammatory markers, and an elevated IgG level but a normal IgE level. Pertinent findings were negative or normal: serum protein electrophoresis test; HIV test; and antinuclear antibodies, creatine kinase, thyroid-stimulating hormone, and serum glucose levels. A full-thickness biopsy specimen of the patient's forearm (pathology slides, below) revealed panniculitis and underlying fasciitis, with lymphocytes, plasma cells, and eosinophils.
The clinical, laboratory, and pathological findings make this a classic presentation of what disease? (Click here for the answer and discussion.)