This is thrombosis in an inflamed vein. If the affected vein is varicose or superficial it will be red and feel like a tender cord. The leg may be diffusely inflamed, making a distinction from cellulitis difficult. There may be fever, leucocytosis and a high ESR. Migratory superficial thrombophlebitis should arouse suspicion of an underlying malignancy or pancreatic disease.
Treatment is based on rest, local heat and NSAIDs.
Antibiotics or anticoagulants rarely help.