1. 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,
Conflicts of interest: none declared
Funding sources: none

2. 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.

3. 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.

4. 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.

5. 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.

6. 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

7. 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.

8. 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.

9. References
1. Drago F, Broccolo F, Rebora A. Pityriasis rosea: an update with a critical appraisal of its possible herpesviral etiology. Journal of the American Academy of Dermatology 2009;61(2): doi: /j.jaad [published Online First: Epub Date]|.
2. Secher L, Weismann K, Kobayasi T. Pityriasis rosea eruption in secondary syphilis: an isomorphic phenomenon? Cutis 1985;35(4):403-4
3. Force USPST. Screening for syphilis infection in nonpregnant adults and adolescents: Us preventive services task force recommendation statement. Jama 2016;315(21): doi: /jama [published Online First: Epub Date]|.
4. Horn T, Kazakis A. Pityriasis rosea and the need for a serologic test for syphilis. Cutis 1987;39(1):81-2
5. Workowski KA, Bolan GA. Sexually transmitted diseases treatment guidelines, MMWR Recommendations and reports : Morbidity and mortality weekly report Recommendations and reports / Centers for Disease Control 2015;64(Rr-03):1-137