Brett
Drug Facts & Comparisons says an adverse reaction of either drug, nabumetone & quinapril, having an incidence of 'defoliative dermatitis'. This probably is a condition in which the hair follicles are defoliated & would fall out, with the hair it grew, and you'd most likely experience reddened, inflamed skin, which probably would cause itching. Your doctor or a dermatologist should be able to make a connection between the symptoms and change your medications appropriately. Best of luck,Brett