There are two causes of fever after using anti-inflammatory drugs. The first reason is that the fever may be due to an allergy. If the fever is due to an allergy and is accompanied by a range of other symptoms, such as difficulty breathing, then desensitizing medication needs to be used to treat the condition and to target the symptoms. The second reason for the use of anti-inflammatory drugs may be due to infection. If the anti-inflammatory drugs to reduce inflammation, the effect is not satisfactory, can not control the infection, in this case, the body will also appear fever. It is recommended to change the antibiotics so that the infection can be controlled and the fever can be controlled.