Xanthoma disseminatum, generalized eruptive histiocytoma, juvenile xanthogranuloma and Hand-Schüller-Christian disease are considered to be separate nosologic entities, but it can be difficult to differentiate them and establish the correct diagnosis in a given case. In this paper, the case of a young man is presented who showed lesions resembling those of generalized eruptive histiocytoma early in the course of disease while the lesions later showed typical signs of xanthoma disseminatum.