Patients exposed to commercial salt solutions (containing calcium and other salts) develop papular skin lesions. Skin biopsy shows follicular plugging and perforation of hair follicles with dermal inflammation and fibrosis.
Solutions associated with these lesions:
(1) salt water, especially that containing calcium and other cations
(2) calcium salt solutions
(3) magnesium salt solutions
(4) other alkaline salt solutions
One proposed mechanism is a chemical burn, possibly from formation of alkali or acids.
NOTE: I saw a television show describing the voyage Captain Bligh and his men in an open boat following the Mutiny on the Bounty. Several of the sailors developed skin lesions related to chronic salt water exposure. All the more reason to wash with fresh water after swimming in the ocean.
Differential diagnosis:
(1) abrasive dermatitis from dried salt on the skin surface
(2) scratching from pruritis