Different clinical picture in early and late onset cortical hyperostosis.

Six cases of Cortical Hyperostosis (C.H.) are presented. The clinical and laboratory features of the disease seem to be related to age at onset. In fact, our cases with a later onset (after the first year of life) are characterized by: a) a longer duration of the disease and a particularly high frequency of relapses; b) the absence of any sign of mandibular involvement; c) the presence of eosinophilia (700-1300/mm3). In two out of three cases having a later onset clinical and laboratory data suggest the hypotesis of a immunoallergic pathogenesis and particularly of cow's milk allergy. A review of the literature appears to confirm the differences between early and late onset forms of C.H. as for as the sites of skeletal involvement and the whole clinical course are concerned.