Have had a yellowish coating on about 1/3 of both my armpit hairs and has a horrible smell uses bar soap daily and never deodorant been there longtime?
Bacterial overgrowth. More than likely you have "trichomycosis axillaris" which is an overgrowth of normal bacteria from your skin called corynebacteria. Try antibacterial soap or hibiclens wash (careful not to get in eyes). If this does not clear it see your dermatologist. You might need either topical or oral antibiotics (erythromycin).