Tungiasis (also known as "Nigua," "Pio and bicho de pie," "Pique") is an inflammatory skin disease caused by infection of the female ectoparasitic Tunga penetrans flea (also known as chigoe flea, jigger, nigua or sand flea), found in the tropical parts of Africa, the Caribbean, Central and South America, and India. Tunga penetrans is the smallest flea in the world, measuring 1mm across. It is also known in Latin America as the nigua and bicho de pie.,
Tungiasis causes skin inflammation, severe pain, itching, and a lesion at the site of infection that is characterized by a black dot at the center of a swollen red lesion, surrounded by what looks like a white halo. Desquamation of the skin is always seen, especially after the flea expands during hypertrophy.
As of 2009, tungiasis is present worldwide in 88 countries with varying degrees of incidence. This disease is of special public health concern in highly endemic areas like Nigeria, Trinidad, Tobago, and Brazil where its prevalence, especially in poor communities, has been known to approach 50%.