RT Journal Article SR Electronic T1 CP-117 Severe calcinosis cutis successfully treated with a topical W/O emulsion of 10% sodium thiosulfate JF European Journal of Hospital Pharmacy: Science and Practice JO Eur J Hosp Pharm FD British Medical Journal Publishing Group SP A47 OP A47 DO 10.1136/ejhpharm-2013-000436.115 VO 21 IS Suppl 1 A1 MA Perez-Moreno A1 C Alvarez del Vayo-Benito A1 AM Villalba-Moreno A1 S Flores-Moreno A1 A Monzon-Moreno A1 J Bernabeu-Wittel YR 2014 UL http://ejhp.bmj.com/content/21/Suppl_1/A47.2.abstract AB Background Calcinosis is caused by accumulation of calcium salts in the tissues, with subcutaneous nodules, atrophy and ulceration over the affected area. Treatment with intravenous sodium thiosulfate has been used, since it inhibits the precipitation of calcium salts and dissolves calcium deposits. Recently, cases successfully treated with topical 10–25% sodium thiosulfate have been described. Purpose To analyse the efficacy and safety of topical treatment with a formulation of 10% sodium thiosulfate in a paediatric patient with iatrogenic calcinosis. To optimise the preparation of the formulation. Case Male 6 years old with primary hypothyroidism and post-surgical hypoparathyroidism treated with calcium gluconate. In January 2013, he was diagnosed with iatrogenic calcinosis presenting stony in consistency erythematous spot in both arms. Topical 10% sodium thiosulfate was prescribed. A literature search was conducted in PubMed to find a suitable formulation. The first sample was stored to check the stability of the emulsion. After starting treatment, the clinical evolution was followed up during successive visits (January–April 2013). Results To achieve greater occlusivity that allowed adequate absorption and a greater pharmacological effect, a topical W/O emulsion was prepared using a commercial product (’cold cream’) as the oily external phase. It was necessary to dissolve the hydrophilic drug in water prior its incorporation in the external phase. The clinical response to treatment was prompt, gradually reducing visible injuries, subcutaneous calcifications, induration and swelling. After 15 days, the pain disappeared completely and mobility was recovered with the help of rehabilitation. The calcified material was gradually expelled as calcium crystals through ulcers over three months. Tolerance of the cream was adequate, with slight temporary pruritus in the first month. The stored emulsion remained stable for 4 months. Conclusions Topical treatment with a W/O emulsion of 10% sodium thiosulfate was effective, as in the published literature (although in one case the concentration was 25% and in the other one injuries were only subcutaneous) and well tolerated (without topical or systemic adverse reactions). Despite the low compatibility between the ionic drug and ‘cold cream’, the emulsion was stable at least 4 months. No conflict of interest.