| • | calcification = the deposition is not organized |
| • | ossification = arranged in the manner seen in normal bone |
| • | most commonly occurs secondary to local tissue alteration or preexisting calcification |
| • | any calcifying disorder of the skin may ossify secondarily |
3 types:
| 1. | dystrophic calcification: |
| • | secondary to tissue damage |
| • | CVD – dermatomyositis (esp. juvenile), CREST |
| • | heel stick in the newborn |
| 2. | metastatic calcification: |
| • | increased serum level of calcium or phosphate (Ca X PO4 > 70) |
| • | destructive bone disease with excessive osteoclast activation (multiple myeloma, leukemia, metastasis, Paget’s disease of bone) |
| • | normocalcemic cases due to increased phosphate in CRF or pseudohypoparathyroidism |
| 3. | idiopathic calcification: |
| • | unassociated with tissue damage or demonstrable metabolic disorder |
| • | idiopathic calcification of the scrotum |
| • | subepidermal calcified nodule (of newborn) |
| • | some cases due to undetected dermatomyositis, SLE, or scleroderma |
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