Letters to the Editor

Serologic Cross-Reactivity of Syphilis, Yaws, and Pinta


Am Fam Physician. 2013 Jan 15;87(2):80.

Original Article: Syphilis: A Reemerging Infection

Issue Date: September 1, 2012

Available at: https://www.aafp.org/afp/2012/0901/p433.html

to the editor: The authors of this article stressed the importance of history, physical examination, and serology in the diagnosis of syphilis. Difficulties can arise when an asymptomatic person who has lived or traveled outside of the United States presents with a positive serology. In addition to Treponema pallidum subsp pallidum, the cause of syphilis, two non–sexually transmitted diseases, yaws (T. pallidum subsp pertenue) and pinta (T. carateum), have the same positive serology. Yaws is prevalent in Africa, Southeast Asia, and the Western Pacific.1 Pinta has occurred mostly in South America and the Caribbean.2 Both yaws and pinta are spread by skin-to-skin contact with infected lesions.

During the initial symptomatic stages, clinical manifestations help in the diagnosis. Yaws presents with an initial primary lesion (papilloma) that is often ulcerative. This lesion has also been described as a framboise (raspberry). After the primary lesion resolves, the secondary lesions appear a few weeks to two years later and resolve without skin scarring.3,4 Pinta presents with a papule or erythematous lesion that is initially hyperpigmented but that becomes depigmented with time.5

Serologic tests for the diagnosis of syphilis (i.e., Venereal Disease Research Laboratory test, rapid plasma reagin test, and fluorescent treponemal antibody absorption assay) are also reactive for pinta and yaws. In addition, it is extremely difficult to differentiate yaws from syphilis in an asymptomatic patient.

The U.S. Department of Health and Human Services stresses the importance of taking a thorough sexual history to assist in differentiating among the treponemal diseases.6 Penicillin G benzathine is the recommended treatment for all three treponemal diseases; a single dose is adequate for yaws, pinta, and primary syphilis, but inadequate for late latent and tertiary syphilis. It is important for clinicians to appropriately diagnose yaws and pinta to guide treatment duration and to avoid inadvertent psychological harm from making the incorrect diagnosis of a sexually transmitted disease.

Author disclosure: No relevant financial affiliations to disclose.


show all references

1. Maurice J. WHO plans new yaws eradication campaign. Lancet. 2012;379(9824):1377–1388....

2. Hook EW. Endemic treponematoses. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa.: Churchill Livingstone/Elsevier; 2010:3056.

3. Radolf JD. Treponema. In: Baron S, ed. Medical Microbiology. 4th ed. Galveston, Tex.: University of Texas Medical Branch at Galveston; 1996.

4. Kapembwa A. Endemic treponematoses. In: Manson P, Cook GC, Zumla A. Manson's Tropical Diseases. 21st ed. London, England: Saunders; 2003:1145–1150.

5. Lukehart SA. Endemic treponematoses. In: Longo D, Fauci A, Kasper D, Hauser S, Jameson J, Loscalzo J. Harrison's Principles of Internal Medicine. 18th ed. New York, NY: McGraw-Hill; 2012:1389.

6. U.S. Department of Health and Human Services. Centers for Disease Control and Prevention; National Center for Emerging and Zoonotic Infectious Diseases. Screening for sexually transmitted diseases during the domestic medical examination for newly arrived refugees. April 6, 2012. http://www.cdc.gov/immigrantrefugeehealth/pdf/std.pdf. Accessed September 15, 2012.

EDITOR'S NOTE: This letter was sent to the authors of “Syphilis: A Reemerging Infection,” who declined to reply.


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