In cases of diffuse thickening of the skin, a thyroid profile with T 3 , T 4 , and TSH should be done. This should also identify hypothyroidism. A positive ANA test with a speckled pattern will help identify scleroderma, but a skin biopsy should also be done. An antisclerodermal antibody titer is also useful if available. Esophageal motility studies will be helpful in early diagnosis. A skin biopsy will help identify many of the other conditions mentioned above. Urine for porphyrins will help identify porphyria.