Lichenoid cutaneous drug reaction at injection sites of granulocyte colony-stimulating factor (filgrastim)

Colony-stimulating factors are widely used for bone marrow recovery after c hemotherapy. Various cutaneous side-effects have been described in most cas es involving neutrophils. We report the first case of lichenoid reaction at injection sites of granulocyte colony-stimulating factor (G-CSF) in a 40-y ear-old patient treated for breast cancer. The eruption cleared after drug withdrawal, no recurrence was observed after drug replacement by granulocyt e-macrophage colony-stimulating factor. Mainly lymphocyte-mediated lichenoi d eruption to G-CSF was shown. Cutaneous side-effects to G-CSF do not share unequivocal pathogeny based on stimulation of neutrophils.