Impetigo in an infant with atopic dermatitis. Atopic dermatitis, also called atopic eczema, is an inflammatory skin reaction that occurs without any obvious external cause. Scratching the affected area can lead to impetigo, a bacterial skin infection caused by Staphylococcus species. It causes the formation of pustules that contain fluid filled with bacteria. The infection is highly contagious. Treatment is with antibiotic drugs. Atopic dermatitis can be treated with soothing ointments and corticosteroid drugs.