The case report of a 2-week-old girl suffering from incontinentia pigmenti (Bloch-Sulzberger Syndrome) with disseminated urticarial erythemas, papules and vesicles at the onset is presented. Histological examination showed eosinophilic spongiosis. The peripheral blood eosinophilia and the development of typical lesions led to the diagnosis of incontinentia pigmenti. Eosinophilic spongiosis and peripheral blood eosinophilia are important symptoms in the diagnosis of atypical incontinentia pigmenti.