Hello, I have gone through your query and understand your concern. The lumps you describe could be any number of things, including cysts (fluid-filled sacs), enlarged lymph nodes, abscesses (pockets of infection), infected hair follicles, or swollen sweat glands. Have you ever noticed whether the lumps appear at a certain time in relation to when you shave your armpits? You could be sensitive to a shaving cream that you re using, you could be inadvertently cutting yourself during shaving, or you could be getting an infection of a hair follicle (folliculitis). You could be allergic to your deodorant as you think of, although the fact that the lumps appear and disappear suggests that they may not be due to deodorant allergy, if you have been using the deodorant all along. You could test whether you re allergic to your deodorant by stopping it for several weeks. If there is a lot of reddening of the skin around the lump, then there could be some infection in the skin (cellulitis) and this requires antibiotics. Thus to differentiate this you need examination by your treating physician and then he may either Drain the pus and put you on antibiotics or both. Hope this helps. Please write back for further queries. Wishing you good health.