Advances in the diagnosis of endemic treponematoses: yaws, bejel, and pinta.

Improved understanding of the differential diagnosis of endemic treponematoses is needed to inform clinical practice and to ensure the best outcome for a new global initiative for the eradication of yaws, bejel, and pinta. Traditionally, the human treponematoses have been differentiated based upon their clinical manifestations and epidemiologic characteristics because the etiologic agents are indistinguishable in the laboratory. Serological tests are still considered standard laboratory methods for the diagnosis of endemic treponematoses and new rapid point-of-care treponemal tests have become available which are extremely useful in low-resource settings. In the past ten years, there has been an increasing effort to apply polymerase chain reaction to treponematoses and whole genome fingerprinting techniques have identified genetic signatures that can differentiate the existing treponemal strains; however, definitive diagnosis is also hampered by widespread unavailability of molecular diagnostics. We review the dilemmas in the diagnosis of endemic treponematoses, and advances in the discovery of new diagnostic tools.

Pigmentary problems in the tropics.

Pigmentary problems are one of the most frequent causes of dermatologic consultation in the tropics. This article deals with diseases seen mostly in tropical countries (ashy dermatosis, lichen planus pigmentosus, frictional dermatitis, pityriasis versicolor, and pinta) and in which a combination of racial, ecologic, nutritional, and social factors all contribute. Other common dermatoses seen worldwide, such as vitiligo and melasma, sometimes acquire dramatic expressions in tropical countries, and their management is usually difficult even for the most experienced dermatologists.

[Immunology of tertiary pinta]. / Imunologia da pinta terciaria.

We've studied the immunological performed of twenty two natives Tikunas suffering from tertiary pinta. Among those, patients had been treated previously (two years earlier) which 2,400,000 IU of G benzathine penicillin, and twelve had no treatment. Both groups demonstrated an increment in the IgM synthesis (72.72%), IgG (50%), indicating the presence of strong antigenic stimuli. The great majority presenting a negative response revealed also a reduction in the cellular immune competence to at least two of the tests performed (92.3%), when were realized the PPD, DNCB and skin grafts tests.

[Histopathological aspects of tertiary pinta]. / Aspectos histopatológicos da pinta terciária.

A study was made of twenty-two biopsies of achromic lesions of Tikuna Indians, carriers of tertiary pinta, inhabitants of the Umariuassu island, on the Peruvian border, ten of the subjects had been treated two years previously with a single dose of penicillin. The histopathological picture was similar for both groups. In most cases (86.36%) slight hyperkeratosis was found on the epidermis, as well as acanthosis (18.18%), with atrophy in only two cases (9.09%). In all cases there was a reduction of the melanin of the basal layer. The inflammatory lymphocyte infiltrate was predominantly perivascular (88.18%). There wasn't any endothelial swelling.