Erythromycin ointment is a topical antibacterial ointment agent with good safety and rare serious adverse reactions. It belongs to grade B in pregnancy classification, i.e. no damage to the fetus has been found in animal experiments, but not confirmed in humans. It can also cause allergic symptoms, with an incidence of 0.5%, manifested as pruritus and urticaria. Severe allergic reactions may also occur, including Stevens-Johnson syndrome as well as toxic epidermal necrolysis relaxation. Although erythromycin ointment is a topical agent, it does not have the GI reactions common to oral and injectable preparations. However, long-term large-scale use can also cause adverse reactions to oral or injectable preparations, such as: gastrointestinal reactions such as nausea and vomiting, liver function impairment, and reversible neurological deafness due to absorption of large amounts of erythromycin into the bloodstream. Due to the abuse of antibacterial drugs, the resistance rate of erythromycin is particularly high, reaching 78.11% overall for Staphylococcus spp. and nearly 100% for Streptococcus pneumoniae. Therefore, it should not be used for a long time or frequently for skin and soft tissue infections, otherwise it will cause resistance to normal skin bacteria and lead to treatment failure.