Intralesional sodium thiosulfate treatment of calcinosis cutis in pseudopseudohypoparathyroidism.

Pseudopseudohypoparathyroidism is an imprinted GNAS spectrum disorder that induces the phenotype of Albright's hereditary osteodystrophy. This phenotype often involves the formation of calcinosis cutis: firm, painful cutaneous eruptions, which are classically difficult to treat. Intralesional sodium thiosulfate has been reported successfully in various cases of calcinosis cutis; however, these reports describe patients with autoimmune or idiopathic calcinosis. This case details the clinical improvement and resolution of calcinosis cutis lesions utilizing intralesional sodium thiosulfate in an adolescent patient with pseudopseudohypoparathyroidism.