Calcium salts can build up in the skin and the tissue beneath it, forming hard, white, or yellow bumps that doctors call calcinosis cutis. The deposits can appear after tissue damage, alongside connective tissue diseases such as scleroderma and lupus, or with abnormal blood calcium or phosphate levels.
Symptoms of calcium deposits on skin range from painless bumps to tender, ulcerated lesions that leak a chalky white material. Treatment depends on the cause and may include medications, surgical removal, laser therapy, or care for the underlying condition.