Pierre Halteh Shari Lipner, MD, PhD A Retrospective Study on Rapid Plasma Reagin Testing in Patients with Pityriasis Rosea Pierre Halteh Research Associate, Department of Dermatology Weill Cornell Medical College Shari Lipner, MD, PhD Assistant Professor, Department of Dermatology Weill Cornell Medical College Address of Correspondence: Dr. Shari R. Lipner, 1305 York Avenue, NY, NY 10021, Email: shl9032@med.cornell.edu Conflicts of interest: none declared Funding sources: none

Background Pityriasis Rosea (PR) is an acute self-limited exanthem characterized by oval erythematous patches with scale, typically beginning with a “herald patch”. Since histopathologic features are not specific, the diagnosis of PR is based on characteristic features from the history and physical examination. Clinically, PR may be difficult to differentiate from secondary syphilis, but a rapid plasma reagin test (RPR) can be used to rule in the latter with 100% sensitivity and 85-99% specificity.

Objectives 1) Assess the frequency of secondary syphilis when the initial clinical impression was PR. 2) Review demographics, social and sexual history, and result of RPR testing.

Methods Single center retrospective study over sixteen years. Inclusion criteria: All patients who were diagnosed with PR and also received RPR testing at the time of diagnosis.

Results 142 patients were included. • 93/142 (65.5%) were female, 99/142 (69.7%) were single. In the majority of cases, the sexual history was unknown; such as: History of sexually transmitted disease (STD) (57.7%) Sexual orientation (62.7%) Number of sexual partners (73.9%), Use of safe-sex practices (89.4%) For social history, 20.4% smoked tobacco, 49.3% drank alcohol, and 1.4% used intravenous (IV) drugs.

Results – Cont’d. Only 2 patients (1.4%) had a reactive RPR test. Both were men, were diagnosed by dermatologists, had RPR titers of 1:32, and positive follow-up treponemal-specific testing. In both cases, the rashes were described as erythematous patches with collarettes of scale in a “Christmas tree” distribution. A “herald patch” was present in one patient. Neither patient had lymphadenopathy, nor involvement of the mucosa or palms/soles

Screening for Syphilis Increased Risk Factors for Syphilis Figure 1: Proposed Algorithm for Syphilis Screening in Patients Diagnosed with Pityriasis Rosea (PR) Screening for Syphilis Clinical Presentation “Herald patch” and oval erythematous patches with collarettes of scale. - Mucosal involvement - Palm/sole involvement Increased Risk Factors for Syphilis Order nontreponemal test: Venereal Disease Research Laboratory [VDRL] or Rapid plasma reagin [RPR] test If positive, confirm with: Treponemal antibody detection test (fluorescent treponemal antibody absorption [FTA-ABS] or Treponema pallidum particle agglutination [TP-PA] test). Men who have sex with men HIV Men 20-29 History of incarceration History of commercial sex work Multiple sexual partners Does not use safe sex practices History of STD Racial/ethic groups (Black, Hispanic, American Indian/Alaska Native, Native Hawaiian/Pacific Islander) Geography (Southern US, Western US, metropolitan areas) One or more risk factors Obtain Social and Sexual History No risk factors Oval erythematous patches with collarettes of scale. - “herald patch” and/or + mucosal involvement and/or + Palm/sole involvement and/or + lymphadenopathy No screening for syphilis recommended. Schedule patient for follow-up for resolution of PR.

Conclusions While our study demonstrated that only 1.4% of patients with clinical diagnosis of PR had syphilis, we advocate that careful social and sexual histories be taken in all patients diagnosed with PR, and syphilis screening performed if risk factors are present. Our recommendation stems from the US Preventive Services Task Force (USPSTF) recommendation for screening of asymptomatic, non-pregnant individuals with increased risk factors for syphilis, as well as similar guidelines from the CDC.

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