eMedicine Specialties > Pediatrics: General Medicine > Dermatology

Pityriasis Rosea: Differential Diagnoses & Workup

Author: Maria R Nasca, MD, PhD, Assistant Professor, Department of Dermatology, University of Catania School of Medicine, Italy
Coauthor(s): Giuseppe Micali, MD, Head, Professor, Department of Dermatology, University of Catania School of Medicine, Italy
Contributor Information and Disclosures

Updated: Sep 24, 2009

Differential Diagnoses

Drug Eruptions
Pityriasis Rubra Pilaris
Erythema Annulare Centrifugum
Psoriasis, Guttate
Erythema Dyschromicum Perstans
Seborrheic Dermatitis
Lichen Planus
Syphilis
Nummular Dermatitis
Tinea Corporis
Pityriasis Alba
Tinea Versicolor
Pityriasis Lichenoides

Other Problems to Be Considered

Viral exanthems
Human immunodeficiency virus infection

Workup

Laboratory Studies

The diagnosis of pityriasis rosea (PR) is made clinically in most cases. In general, laboratory tests are not necessary or helpful, with the following exceptions:

  • A potassium hydrochloride (KOH) test may be especially helpful when only the herald patch is present to help diagnose tinea corporis.
  • A rapid plasma reagin (RPR) or venereal disease research laboratory (VDRL) test should be performed to rule out secondary syphilis. Titration of the RPR test is recommended to detect the prozone phenomenon. Other features that would suggest syphilis include patchy alopecia, salmon-colored plaques on the palms of the hands and soles of the feet, diffuse adenopathy, white papules of the oral mucosa, and condylomata lata.
  • HIV testing should also be considered.

Procedures

  • A skin biopsy can be obtained when the eruption is atypical, the diagnosis is uncertain, or the disease has not resolved after 3-4 months. It shows nonspecific features of a subacute or chronic dermatitis but may be helpful in ruling out other diseases in the differential diagnosis.

Histologic Findings

Histologic examination is usually unnecessary but may be performed in doubtful cases to rule out other conditions, especially in atypical forms. Histological findings are nonspecific and include the following:

  • Hyperplasia with mild acanthosis, a thinned granular layer, focal parakeratosis and spongiosis, and possible lymphocyte exocytosis, in the epidermis.
  • Perivascular lymphocytic infiltrate, with histiocytes, eosinophils, monocytes, and few extravasated erythrocytes in the dermis.

More on Pityriasis Rosea

Overview: Pityriasis Rosea
Differential Diagnoses & Workup: Pityriasis Rosea
Treatment & Medication: Pityriasis Rosea
Follow-up: Pityriasis Rosea
Multimedia: Pityriasis Rosea
References
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References

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  2. González LM, Allen R, Janniger CK, Schwartz RA. Pityriasis rosea: an important papulosquamous disorder. Int J Dermatol. Sep 2005;44(9):757-64. [Medline].

  3. [Guideline] Finnish Medical Society Duodecim. Syphilis. EBM Guidelines. Jun 6 2008.

  4. Blauvelt A. Skin diseases associated with human herpesvirus 6, 7, and 8 infection. J Investig Dermatol Symp Proc. Dec 2001;6(3):197-202. [Medline].

  5. Broccolo F, Drago F, Careddu AM, Foglieni C, Turbino L, Cocuzza CE, et al. Additional evidence that pityriasis rosea is associated with reactivation of human herpesvirus-6 and -7. J Invest Dermatol. Jun 2005;124(6):1234-40. [Medline].

  6. Canpolat Kirac B, Adisen E, Bozdayi G, et al. The role of human herpesvirus 6, human herpesvirus 7, Epstein-Barr virus and cytomegalovirus in the aetiology of pityriasis rosea. J Eur Acad Dermatol Venereol. Jan 2009;23(1):16-21. [Medline].

  7. Chuh AA, Chan PK, Lee A. The detection of human herpesvirus-8 DNA in plasma and peripheral blood mononuclear cells in adult patients with pityriasis rosea by polymerase chain reaction. J Eur Acad Dermatol Venereol. Jul 2006;20(6):667-71. [Medline].

  8. Drago F, Malaguti F, Ranieri E, Losi E, Rebora A. Human herpes virus-like particles in pityriasis rosea lesions: an electron microscopy study. J Cutan Pathol. Jul 2002;29(6):359-61. [Medline].

  9. Kempf W, Adams V, Kleinhans M, Burg G, Panizzon RG, Campadelli-Fiume G, et al. Pityriasis rosea is not associated with human herpesvirus 7. Arch Dermatol. Sep 1999;135(9):1070-2. [Medline].

  10. Watanabe T, Kawamura T, Jacob SE, Aquilino EA, Orenstein JM, Black JB, et al. Pityriasis rosea is associated with systemic active infection with both human herpesvirus-7 and human herpesvirus-6. J Invest Dermatol. Oct 2002;119(4):793-7. [Medline].

  11. Chuh A, Chan H, Zawar V. Pityriasis rosea--evidence for and against an infectious aetiology. Epidemiol Infect. Jun 2004;132(3):381-90. [Medline].

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  13. Drago F, Broccolo F, Zaccaria E, Malnati M, Cocuzza C, Lusso P, et al. Pregnancy outcome in patients with pityriasis rosea. J Am Acad Dermatol. May 2008;58(5 Suppl 1):S78-83. [Medline].

  14. Robati RM, Toossi P. Plantar herald patch in pityriasis rosea. Clin Exp Dermatol. Mar 2009;34(2):269-70. [Medline].

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  17. Amer A, Fischer H, Li X. The natural history of pityriasis rosea in black American children: how correct is the "classic" description?. Arch Pediatr Adolesc Med. May 2007;161(5):503-6. [Medline].

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  19. Sharma PK, Yadav TP, Gautam RK, Taneja N, Satyanarayana L. Erythromycin in pityriasis rosea: A double-blind, placebo-controlled clinical trial. J Am Acad Dermatol. Feb 2000;42(2 Pt 1):241-4. [Medline].

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  23. Arndt KA, Paul BS, Stern RS, Parrish JA. Treatment of pityriasis rosea with UV radiation. Arch Dermatol. May 1983;119(5):381-2. [Medline].

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Further Reading

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Keywords

pityriasis rosea, PR, fine pink scale, inverse pityriasis rosea, inverse PR, vesicular pityriasis rosea, vesicular PR, bullous pityriasis rosea, bullous PR, papular pityriasis rosea, papular PR, syphilis, roseola, bone marrow transplantation, mononucleosis, influenza, parainfluenza, Epstein-Barr virus, parvovirus B19, cytomegalovirus, herpesvirus, infection, acetylsalicylic acid, barbiturates, bismuth, captopril, clonidine, gold, imatinib, isotretinoin, ketotifen, levamisole, metronidazole, omeprazole, D-penicillamine, terbinafine, Bacillus Calmette-Guérin vaccine, diphtheria vaccine, miscarriage, prematurity, neonatal hypotonia, hyporeactivity, lymphadenopathy, herald patch, tinea corporis, treatment, diagnosis

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Contributor Information and Disclosures

Author

Maria R Nasca, MD, PhD, Assistant Professor, Department of Dermatology, University of Catania School of Medicine, Italy
Disclosure: Nothing to disclose.

Coauthor(s)

Giuseppe Micali, MD, Head, Professor, Department of Dermatology, University of Catania School of Medicine, Italy
Giuseppe Micali, MD is a member of the following medical societies: American Academy of Dermatology
Disclosure: Nothing to disclose.

Medical Editor

Kevin P Connelly, DO, Clinical Assistant Professor, Department of Pediatrics, Division of General Pediatrics and Emergency Care, Virginia Commonwealth University; Medical Director, Paws for Health Pet Visitation Program of the Richmond SPCA; Pediatric Emergency Physician, Emergency Consultants Inc, Chippenham Medical Center
Kevin P Connelly, DO is a member of the following medical societies: American Academy of Pediatrics, American College of Osteopathic Pediatricians, and American Osteopathic Association
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from financial planner; Avanir Pharma Stock Investment from financial planner ; WebMD Salary and stock Employment and investment from financial planner

Managing Editor

Robert A Schwartz, MD, MPH, Professor and Head, Dermatology, Professor of Pathology, Pediatrics, Medicine, and Preventive Medicine and Community Health, UMDNJ-New Jersey Medical School
Robert A Schwartz, MD, MPH is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American College of Physicians, and Sigma Xi
Disclosure: Nothing to disclose.

CME Editor

Merrily P M Poth, MD, Professor, Department of Pediatrics and Neuroscience, Uniformed Services University of the Health Sciences
Merrily P M Poth, MD is a member of the following medical societies: American Academy of Pediatrics, Endocrine Society, and Lawson-Wilkins Pediatric Endocrine Society
Disclosure: Nothing to disclose.

Chief Editor

Dirk M Elston, MD, Director, Department of Dermatology, Geisinger Medical Center
Dirk M Elston, MD is a member of the following medical societies: American Academy of Dermatology
Disclosure: Nothing to disclose.

 
 
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