We report a 58-year-old patient with acute myeloid leukaemia who developed an oedematous erythema resembling Sweet's syndrome, accompanied by atypical erythema nodosum and bullous pyoderma gangrenosum. Examination of skin biopsies showed dense infiltration with mature neutrophils, although there was peripheral blood leucocytopenia. The oedematous erythema worsened after he was treated with granulocyte-colony-stimulating factor (G-CSF), which was given for his leucocytopenia. We suggest that when a neutrophilic dermatosis complicates leukaemia, alternatives to G-CSF should be considered for the treatment of leucocytopenia. Corticosteroids were very effective in controlling the skin lesions in our patient.