Studies with 47Ca in patients with calcinosis cutis

Physiological and toxicological changes in the skin resulting from the action and interaction of metal ions

The human environment contains more than 50 metal or metalloid elements. At least 15 are recognized as trace elements, with zinc, calcium, copper, magnesium, and iron having specific roles in skin morphogenesis and function. The present review focuses on the presumed role of metal ions in the skin, their competition for carrier proteins, and membrane receptors. Evidence presented shows that the balance of trace metal ions is critical for normal skin and repair mechanisms following injury. Xenobiotic ions can impair this balance, leading to pathological change. The skin acts as an organ of elimination of excess trace metals and xenobiotic ions from the body, but mechanisms of voidance vary for different metals. Metal ions are an important cause of allergies, and evidence is presented to show that the majority of metals or metal compounds can induce allergic changes. Except for chromium and nickel, which are among the most common human allergens, animal models have provided little information. At least cadmium, thorium, lead, chromium, nickel, beryllium, and arsenic and proven or putative carcinogens in animals or humans on the basis of cytological or epidemiological evidence. However, only arsenic exhibits a clear predilection for the skin. Other metals such as gold can induce subcutaneous sarcoma following injection, but the relevance of this observation in terms of human occupational risk is discounted.

Parathyroid hormone and calcium metabolism in generalized scleroderma. Increased PTH level and secondary hyperparathyroidism in patients with aberrant calcifications. Prophylactic treatment of calcinosis

Parathyroid hormone (PTH) in serum and biochemical parameters of calcium metabolism were analysed in 45 patients with systemic sclerosis. Calcification of the skin and subcutaneous tissue was assessed by X-ray examination of the hands. Analyses disclosed secondary hyperparathyroidism (increased PTH in serum, low calcium 'ion' in serum, decreased urinary excretion of calcium and phosphate), in particular in patients with calcinosis (P less than 0.05) as compared to those with no calcinosis. The duration of systemic sclerosis was longer in patients with calcinosis (P less than 0.05). The calcinosis type of systemic sclerosis is characterized by secondary hyperparathyroidism developed during the progression of the disease. A hypothesis is made regarding calcium metabolism in the early no-calcinosis (with increased synthesis of Vitamin D) and late calcinosis types. PTH may stimulate aberrant calcification. The hypothesis implicates that prophylactic treatment with Vitamin D in low dose may prevent calcinosis.

Surgical treatment of calcinosis cutis in the upper extremity

Recent surgical experience with 11 cases of calcinosis cutis has given the authors an opportunity to define the role of surgery in the management of this condition. In scleroderma associated with dermatomyositis, when complications or disability arise from one or more areas of calcinosis, surgery may give significant palliation. Wound healing, although a potential problem, does not constitute a contraindication to operative treatment. Damage to deep structures usually is avoidable, but in some instances is a reasonable trade-off for the benefits obtained. Follow-up has confirmed that surgery is beneficial to patient comfort and function, even in the few patients in whom some calcinosis recurred.