Eosinophils in the epidermis are usually associated with spongiosis,hence the term eosinophilic spongiosis.Again allergic contact dermatitis is the most likely cause but other conditions include bullous pemphigoid,pemphigus,erythema toxicum neonatorum,arthropods bites particularly scabies,eosinophilic pustular folliculitis and in the female neonate also consider incontinentia pigmenti.
Adapted from Practical Dermatopathology by Ronald Rapini. Elsevier Mosby