Since the discovery by Demarquay in 1863 of filarial embryos in the exudate of a chylous hydrocele, filariasis has been considered the etiological factor in the production of lymphangitis and elephantiasis in the tropics. Other conditions attributed to filariasis such as lymph scrotum, chyluria, hydrocele and orchitis will not be discussed in this report.
The incidence of elephantoid fever and elephantiasis in Porto Rico is very high. This is probably due to the excess of population and unhygienic housing among the poor classes. The disease is more or less uniformly distributed throughout the island with a few endemic foci here and there such as Puerta de Tierra (a suburb of the capital) and the city of Aguadilla in the western part of the island.
The clinical picture of lymphangitis as it is seen in Porto Rico does not differ a great deal from that in other tropical countries.