Redness and swelling with small bumps around the baby’s anus may be caused by perianal dermatitis or perianal abscess. 1. Perianal dermatitis: baby redness and swelling around the anus with small bumps, may be caused by inflammatory infections. The cause of occurrence is mostly diaper rash, which is a common skin disease among infants. Mainly due to the diaper is not changed in time, resulting in infection. Daily attention to baby skin cleaning, timely change of diapers, urine and feces should be timely cleaning, keep private parts dry, more sunshine, try not to use diapers, can improve the above phenomenon. 2. Perianal abscess: if the baby around the anus is red and swollen with small bumps, if the baby is more painful when pressing the small bumps, indicating that the pain is more serious, may be a perianal abscess. If the baby appeared perianal redness and swelling with small bumps, can be closely observed, if there is an abnormality in a timely manner to seek medical attention, follow the doctor’s instructions for symptomatic intervention.