A lot of small red pimples on the face to consider the possibility of pimple urticaria, folliculitis, rosacea, psoriasis, etc., as follows: 1, pimple urticaria: mostly occurs in the summer, insects, parasites and other easy to breed the season, the bite of the bugs produce a perverse reaction; 2, folliculitis, acne: due to the infection of Propionibacterium acnes, combined with endocrine disorders caused by inflammatory skin diseases; 3, rosacea: due to genetic factors, hot and cold stimuli, long-term application of large amounts of glucocorticosteroid ointment caused by inflammatory diseases of the skin; 4, psoriasis: silver-white scales on the surface of the small red pimples can be seen due to the multi-genetic dominant inheritance caused by the.