The cause of subcutaneous fibroids is still unclear and may be related to genetic factors, systemic lipid metabolism and chronic inflammatory reactions, etc. Because they are common benign tumors, they usually do not require treatment. The cause of subcutaneous cysts is complex and may be related to congenital developmental abnormalities, local trauma, infectious factors and genetic factors, asymptomatic people do not need treatment, if the condition is heavy or the volume of a single lesion is large, surgery can be chosen to remove it if necessary. 3, to consider the possibility of erythema nodosum, the main cause of which is related to infection, especially hemolytic streptococcus, leukoaraiosis can also lead to.