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, etc. prone to breeding season, the bite of insects 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 glucocorticosteroid ointment caused by a large number of inflammatory diseases of the skin; 4, psoriasis: the silver-white scales can be seen on the surface of the small red pimples due to the multi-genes dominant genetic caused by the.