The American tropics claim a number of characteristic new cutaneous disease entities.1 In this group are included such fascinating members as verruga peruana, pinta, epidemic pemphigus, American leishmaniasis and American onchocerciasis. The last-named disease not only is novel and interesting but is of great importance to public health in Guatemala and Mexico,2 where it is widespread in certain regions of 1,100 to 5,000 feet (330 to 1,500 meters) elevation above sea level along the Pacific coast. With the gradual northward spread of onchocerciasis up from Central America and with the presence of the insect vector, the Simulium, in certain of the western communities of the United States, "it has been suggested that the disease may spread to the United States by infected immigrants coming over the border from Mexico, and that it may later become endemic in this country."3 Up to