We thank Dr. Hakan and collaborators for their interesting information provided as a reaction to our recent paper [1].

Their approach is original, although their hypothesis needs to be discussed in further details.

Biphosphonates are adsorbed on to hydroxyapatite crystals in bone and slow down their rate of growth and dissolution. As a result, the rate of bone turnover decreases. Previously, other bisphosphonates, e.g., pamidronate, have been given in several cases of subcutaneous fat necrosis and found to be effective in hypercalcaemia–hypercalcuria conditions. Although biphosphonates are generally preserved for the more resistant cases and considered as second line agents for the treatment of subcutaneous fat necrosis in newborns, some have suggested that early use can prevent nephrocalcinosis. Alendronate is a new addition to the series of bisphosphonates tried for SCFN. This case report appears to be the first one reporting alendronate sodium use in SCFN. But it is not clear why this one was chosen among the bisphosphonates and whether it has got any superiority in comparison to the use of pamidronate while treating SCFN. As the physiopathological mechanism of SCFN is still not fully understood, the impact of alendronates on the natural history of SCFN and its long-term side effects need to be carefully monitored and its safety needs to be clearly established in the vulnerable neonatal population.