Laboratory Studies
Pinta is most often a clinical diagnosis.
Serological tests are considered the standard laboratory method for the diagnosis of endemic treponematoses, including pinta. Treponemes can be demonstrated by darkfield examination of exudates from early lesions.
Nontreponemal test results (ie, rapid plasma reagent [RPR], Venereal Disease Research Laboratory [VDRL] test) are positive in all stages of pinta except very early lesions. Confirmatory treponemal test results (ie, T pallidum hemagglutination [TPHA], microhemagglutination T pallidum [MHA-TP], fluorescent treponemal antibody absorption [FTA-Abs]) are also positive but are not practical in remote areas. [10]
New rapid point-of-care treponemal tests have become available in resource-poor settings. Whole-genome fingerprinting techniques and polymerase chain reaction (PCR) are also available but currently limited for research purposes. [10]
Histologic Findings
Findings of pinta and yaws are similar, but pinta does not cause ulcer formation. In early lesions, mild acanthosis is present with migration of lymphoid cells into the epidermis. In the late stage, irregular acanthosis or epidermal atrophy occurs. Treponemes can be demonstrated in the epidermis in primary and secondary lesions using silver stain. They are absent in late achromic lesions. [4, 9]
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Erythematosquamous plaque of early pinta. Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.
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Violaceous psoriatic plaque of early pinta. Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.
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Late pigmented pinta (blue variety). Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.
