[Perforating milia-like idiopathic calcinosis of the extremities in Down syndrome].

INTRODUCTION: Several skin diseases can be seen in patients with trisomy 21. We report a case of miliary calcinosis of the extremities. CASE REPORT: A 15-year old adolescent with Down's syndrome presented small papular miliary lesions which had developed over 18 months and tended to discharge a chalk-like substance via the epidermis. Approximately 15 lesions were present on the hands and feet. Histologically, there was a well-delimited calcium deposit in the superficial dermis. There was no alteration in phosphorus/calcium metabolism. Brain CT-scan and cardiac echography did not reveal any calcifications. DISCUSSION: Miliary calcinosis cutis may not be exceptional in Down's syndrome, although only 9 observations have been reported. Preferential localizations include the hands, wrists and feet. Association with syringoma has been noted but would appear to be fortuitous. Transepidermal elimination of the calcium deposits is frequent. Pathogenic hypotheses include precipitation of calcium salts in sudation products and/or increased synthesis by fibroblasts. The association with trisomy 21 appears to be significant since only three cases have been reported in patients with normal karyotypes. This entity should be individualized as perforating milia-like idiopathic calcinosis cutis of the extremities.