As I see Er on those pictures have spikes also...this may be due to high oslomarity of the staining solutions that cause such things...that is my experience and I dont exclude the possible viral infection.
This appearance is a kind of cell blebbing.You should make PB Flow cytometric analysis for the elimination of hematological malignancies or transient abnormal myelopoiesis .
I noticed that some of the red cells also have irregular membranes. So my first thought would be to check your staining technique. Are the cells drying too slowly on the slide prior to commencement of staining?