[Strontium ranelate-induced DRESS syndrome]

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a severe form of adverse drug reaction. Strontium ranelate has recently been authorised for postmenopausal osteoporosis. We report a case of strontium ranelate-induced DRESS complicated by linear Ig A dermatosis due to vancomycin.

A 77-year-old woman with osteoporosis had been treated by strontium ranelate for 4 weeks when she developed a febrile generalized skin rash. Blood tests showed eosinophilia (12.74 × 10(9)/L) and liver damage. A diagnosis of DRESS was made, leading to discontinuation of strontium ranelate and prescription of systemic corticosteroids. Two days later, methicillin-resistant Staphylococcus aureus bacteraemia occurred and treatment with vancomycin was started. The liver dysfunction resolved. After two weeks of antibiotherapy, bullous lesions were noted on the thighs. Skin biopsy results suggested a diagnosis of linear IgA bullous dermatosis. Vancomycin was stopped. Two weeks later, the eruption resolved. The eosinophil count gradually returned to normal after four months of corticosteroid therapy.

More than 15 cases of DRESS syndrome have been reported in Europe, including 2 deaths related to ranelate strontium, prompting European health authorities to publish a warning concerning the risk of strontium ranelate-induced DRESS. A particular feature of our patient was complication with linear IgA bullous dermatosis caused by vancomycin. In conclusion, it is essential to be aware of the risk of severe cutaneous reaction to strontium ranelate, a new drug used to treat osteoporosis.