AUTHOR AND EDITOR INFORMATION

Section 1 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

INTRODUCTION

Section 2 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Background

Pityriasis rosea (PR) means fine pink scale. PR was first described by Camille Melchior Gilbert in 1860. PR is a common skin disorder observed in otherwise healthy people, most frequently children and young adults. PR manifests as an acute, self-limiting, papulosquamous eruption with a 6- to 8-week duration.

Pathophysiology

The specific cause of the disorder remains unclear; however, strong evidence suggests that it is due to a reactivation of latent human herpesvirus-6 (HHV-6) and human herpesvirus-7 (HHV-7) infection. The seasonal occurrence, clinical course, possibility of epidemic occurrence, presence of occasional prodromal symptoms, and infrequent likelihood of recurrences have all suggested an infectious etiology.

The disease has been associated with recent upper respiratory infections. Increased incidence among groups with close physical contact (eg, families, students, military personnel) has been reported, which suggests a transmissible agent. A higher incidence among patients with decreased immunity (eg, pregnant women, bone marrow transplant patients) has been noted. Additionally, ampicillin has been found to increase the distribution of the eruption; this phenomenon bears a striking resemblance to the effect of ampicillin on the rash of infectious mononucleosis. Many common infectious agents have been studied (eg, influenza A and B; parainfluenza I, II, III; Mycoplasma) and shown not to be causative. Recent reports using polymerase chain reaction (PCR) analysis have suggested a role for HHV-7 and HHV-6, but this has not been confirmed in later studies.

Despite the prevailing opinion that PR is caused by an infectious agent, it does not appear to be very contagious; household contacts and schoolmates usually do not develop the disease.

PR-like eruptions can also occur in association with many drugs. These include barbiturates, bismuth, captopril, clonidine, diphtheria toxoid, gold, isotretinoin, ketotifen, levamisole, metronidazole, and D-penicillamine. Drug-induced PR often lasts longer than non–drug-induced PR.

Frequency

International

PR is present worldwide and occurs year round, although it may be more common in the fall and spring.

PR accounts for approximately 2% of outpatient visits in dermatology.

Mortality/Morbidity

PR is a self-limiting, benign disorder with a recurrence rate of less than 3%. It usually lasts for 6-8 weeks but can last as long as 3-6 months. Postinflammatory pigment changes are common, especially in black people. Bacterial superinfections are rarely observed.

Race

PR shows no racial specificity, although black people may have more extensive or atypical disease.

Sex

PR occurs slightly more often in females than in males. The female-to-male ratio is reported as 2:1 or 3:2 in the United States.

Age

PR is observed in people of all age groups, although it is most common in persons aged 10-35 years. The youngest patient reported in the literature was aged 3 months, and the oldest was aged 85 years.

CLINICAL

Section 3 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

History

• A small number of patients (5%) have mild prodromal symptoms, such as fatigue, headache, nausea, anorexia, chills, and arthralgias. Lymphadenopathy may occur prior to onset of the rash.
• Some patients (8-20%) may have a history of recent upper respiratory infection.
• Rash may be pruritic (25-75% of cases), especially in the first few weeks of the illness.
• Approximately 50-80% of patients present with a herald patch.

Physical

• Primary herald patch
• • A herald patch is a pink macule or papule that gradually expands over a few days to become a 2- to 10-cm, salmon-pink–to–brown, oval plaque. The lesion is scaly and may exhibit central clearing, which mimics tinea corporis.
  • Primary herald patch is most commonly observed on the trunk, neck, and proximal extremities.
• Subsequent lesions
• • Numerous subsequent lesions occur in crops 1-2 weeks (range 1-30 d) after onset of the herald patch and usually involve the thorax, back, abdomen, and proximal extremities. They are not usually observed on the face, hands, and feet.
  • These lesions occur as maculars and papules that are elliptical or ovular in shape and 0.5-1.5 cm across. A fine scale is usually present. A characteristic feature is a collarette appearance to the scale, with the edges of the scale peripherally attached and lifted up near the center of the lesion. However, unlike classic tinea corporis, the scale does not extend to the edge of the lesion.
  • The distribution is diffuse, with the long axis of the lesions running parallel to skin tension lines. This produces a Christmas tree pattern on the back.
• Pigment changes: With resolution of the eruption, postinflammatory pigment changes can be observed.
• Oral findings: Oral lesions are infrequently observed but may include plaques, petechiae, and ulcers (with or without raised borders).
• Variants and atypical forms
• • Approximately 20% of patients present with atypical forms of pityriasis rosea (PR).
  • A predominantly papular form is believed to occur more commonly in young children, pregnant women, and black people.
  • Lesions of the face, hands, and feet are occasionally observed. The face may be more commonly affected in young children, pregnant women, and black people. The physician should consider secondary syphilis in the differential diagnosis, especially when involvement of the palms and soles is present.
  • Lesions can be vesicular, pustular, urticarial, purpuric, or even erythema multiform–like, making the diagnosis difficult.
  • An inverse pattern is also observed, with most of the lesions occurring on the face and extremities.
  • Secondary eczematous changes can occur if pruritus is severe.
  • Black people tend to have a widespread form with hyperpigmentation upon resolution.

Causes

See Pathophysiology.

DIFFERENTIALS

Section 4 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Other Problems to be Considered

Drug eruptions
Guttate psoriasis
Lichen planus
Nummular eczema
Pityriasis lichenoides
Tinea corporis
Viral exanthems

WORKUP

Section 5 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Lab Studies

• The diagnosis 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. 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.

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 it may be helpful to rule out other diseases in the differential diagnosis.

TREATMENT

Section 6 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Medical Care

• Treatment is unnecessary in most cases because pityriasis rosea (PR) is usually a self-limiting disease with no sequelae. Patient education and reassurance is all that is needed.
• In cases of severe pruritus, various measures may be taken to provide symptomatic relief:
• • Patients should avoid harsh soaps, tight clothing, and scratching.
  • Bland emollients may be helpful. Topical preparations with calamine, menthol, pramoxine, colloidal starch, and oatmeal may also be beneficial.
  • Topical steroids may help alleviate the pruritus. The sedative effect of the antihistamines may help the patient to sleep better at night. On occasion, systemic steroids (prednisone 0.5-1 mg/kg/d for 7 d) can be used in patients with severe pruritus. Some dermatologists also use systemic steroids in cases with vesicular lesions or if concern for significant postinflammatory hyperpigmentation exists. Systemic steroids in large doses suppress pruritus and the exanthem. Systemic steroids may exacerbate the disease in some patients.
  • In a small clinical trial, 1 g of erythromycin taken orally 4 times daily in adults or 25-40 mg/kg divided 4 times daily in children for 2 weeks has shown early resolution of symptoms and may be of benefit. Treatment in the first week of symptom onset with 1 g of acyclovir taken orally 5 times a day for 7 days in adults has been shown to shorten the duration of disease in one clinical trial and may be of benefit.
  • UV-B (5 daily erythemogenic doses) may relieve pruritus in as little as 24 hours, but it may increase the incidence of postinflammatory hyperpigmentation.

Consultations

Patients with severe pruritus or disease that requires systemic steroids or patients who desire UV-B therapy should be referred to a dermatologist.

Activity

No restriction of activity or isolation is necessary.

MEDICATION

Section 7 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Treatment is not necessary because pityriasis rosea (PR) is usually a self-limiting disease with no sequelae. In cases of severe pruritus, oral antihistamines can be used for their sedating effect in attempt to prevent scratching at night. Topical agents may be beneficial to soothe and moisturize the skin (eg, calamine lotion, zinc oxide, menthol-phenol preparations, colloidal starch, oatmeal).

Drug Category: Antihistamines

These agents are used for the sedating effect to decrease scratching at night. Act by competitive inhibition of histamine at the H1 receptor.

Drug Name	Diphenhydramine (Benadryl, Benylin)
Description	For symptomatic relief of symptoms caused by release of histamine. Available as an over-the-counter product.
Adult Dose	25-50 mg PO q6-8h prn; not to exceed 400 mg/d
Pediatric Dose	5 mg/kg/d PO divided q6h; not to exceed 300 mg/d
Contraindications	Documented hypersensitivity; MAOIs
Interactions	Potentiates effect of CNS depressants; because of alcohol content, do not administer syr dosage form to patients taking medications that can cause disulfiramlike reactions
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	May exacerbate angle closure glaucoma, hyperthyroidism, peptic ulcer, and urinary tract obstruction; infants and young children more likely to experience significant CNS effects; may cause sedation, nausea, vomiting, xerostomia, and blurred vision; paradoxical stimulation observed in children; adjust dose in renal failure

Drug Category: Corticosteroids, topical

Over-the-counter low-to-medium potency steroids may help relieve itching. Effectiveness is due to anti-inflammatory and immunosuppressive properties.

FOLLOW-UP

Section 8 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Further Outpatient Care

• Pityriasis rosea (PR) is a self-limiting disease, and no follow-up is necessary in most cases.
• Patients with moderate-to-severe pruritus who are receiving topical steroids should have follow-up by phone or by a return visit in 1-2 weeks.

Complications

• Postinflammatory hyperpigmentation is the most common long-term complication.

Prognosis

• Prognosis is excellent. The recurrence rate is approximately 2%.

Patient Education

• Patients must be told that PR is a benign disease that resolves over 6-12 weeks without treatment. Lesions do not result in scars, although postinflammatory pigment changes can occur.

REFERENCES

Section 9 of 9

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

• Allen RA, Janniger CK, Schwartz RA. Pityriasis rosea. Cutis. Oct 1995;56(4):198-202. [Medline].
• 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].
• Crissey JT. Pityriasis rosea. Pediatr Clin North Am. 1956;3:801-809.
• Drago F, Vecchio F, Rebora A. Use of high-dose acyclovir in pityriasis rosea. J Am Acad Dermatol. Jan 2006;54(1):82-5. [Medline].
• Parsons JM. Pityriasis rosea update: 1986. J Am Acad Dermatol. Aug 1986;15(2 Pt 1):159-67. [Medline].
• Pomeranz AJ, Fairley JA. The systematic evaluation of the skin in children. Pediatr Clin North Am. Feb 1998;45(1):49-63. [Medline].
• Sharma PK, Yadav TP, Gautam RK, et al. Erythromycin in pityriasis rosea: A double-blind, placebo-controlled clinical trial. J Am Acad Dermatol. Feb 2000;42(2 Pt 1):241-4. [Medline].
• Watanabe T, Kawamura T, Jacob SE, 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].

Article Last Updated: Nov 21, 2006