AUTHOR INFORMATION

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Authored by Richard Lichenstein, MD, Director, Associate Professor, Department of Pediatric Emergency Medicine, University of Maryland Medical Center

Richard Lichenstein, MD, is a member of the following medical societies: American Academy of Pediatrics

Edited by Jerry Balentine, DO, Professor of Emergency Medicine, New York College of Osteopathic Medicine; Medical Director, Saint Barnabas Hospital; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Mark W Fourre, MD, Program Director, Department of Emergency Medicine, Maine Medical Center, Associate Clinical Professor, Department of Surgery, University of Vermont School of Medicine; John Halamka, MD, Chief Information Officer, CareGroup Healthcare System, Assistant Professor of Medicine, Department of Emergency Medicine, Beth Israel Deaconess Medical Center; Assistant Professor of Medicine, Harvard Medical School; and Pamela Dyne, MD, Program Director, Associate Professor, Department of Medicine, Division of Emergency Medicine, University of California at Los Angeles School of Medicine

Author's Email:	Richard Lichenstein, MD
Editor's Email:	Jerry Balentine, DO

eMedicine Journal, June 13 2006, VOLUME 7, Number 6

INTRODUCTION

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Background: Pityriasis rosea (PR) is an acute and characteristic exanthem that has been described for more than 2 centuries. Initially, a primary plaque, called a herald patch, is seen. The herald patch is followed by a distinctive, generalized rash 1-2 weeks later. The rash lasts approximately 2-6 weeks.

Pathophysiology: The primary plaque is seen on the skin in 50-90% of cases a week or more before the onset of the eruption of smaller lesions. This secondary eruption occurs 2-21 days later in crops following the lines of cleavage of the skin. On the back, this eruption produces a "Christmas tree" pattern.

Frequency:

• In the US: The overall prevalence of PR has been calculated to be 0.13% in men and 0.14% in women. The prevalence reported at dermatologic centers has been between 0.3 and 3%.

• Internationally: An increase in the prevalence of PR has been reported in Uganda. No change in the prevalence of PR has been reported in Sweden. It has also been seen in the United Kingdom, Nigeria, Sudan, Brazil, Lagos, Singapore, Turkey, Kuwait, and Hong Kong.

Mortality/Morbidity: PR is a self-limited benign illness.

Sex: PR is reported to occur equally in the two sexes or slightly more often in females. The ratio of men to women varies from 1:1.43.

Age: PR is most common in children and young adults. Prevalence of PR rises during childhood and is most common in persons aged 15-40 years. PR is rare in infants and in elderly persons; however, it has been reported in infants as young as 3 months.

CLINICAL

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History:

• Pityriasis rosea (PR) may have prodromal symptoms (eg, malaise, nausea, anorexia, fever, joint pain, lymph node swelling, headache) that may precede the appearance of the herald patch.

• Pruritus, which may be intense, is present in 75% of cases.

• Ask the patient whether this is the first episode or a recurrence.

Physical:

• The herald patch measures 1-2 cm in diameter. The patch is characterized as oval or round with a central, wrinkled, salmon-colored area and a dark red peripheral zone. The areas are separated by a collarette of fine scales. The herald patch is usually located on the trunk but can be seen on the neck or extremities.

• The secondary eruption appears at its maximum in about 10 days.

• The secondary eruption is symmetric and localized, predominantly to the trunk and adjacent areas of the neck and extremities.

• Involvement is maximal over the abdomen and anterior and dorsal surfaces of the thorax.

• The secondary lesions appear as the primary patch in miniature, with the two red zones separated by the scaling ring. They are distributed in a Christmas tree pattern with their long axes following the lines of cleavage of the skin. In children under the age of 5 years, papular PR may be seen with a similar distribution.

• In atypical PR (20% of patients), the herald patch may be missing or confluent with other lesions.

• The distribution of the rash may be peripheral, and facial involvement may be seen in children. Involvement of the axilla and groin (inverse variant) can also be seen.

• The lesions of PR may be large (PR gigantea), urticarial (PR urticata), vesicular, pustular, purpuric, and erythema multiforme–like.

• Hypopigmentary and hyperpigmentary skin changes may follow the inflammatory stage. In patients with black skin, hyperpigmentation is more common.

• Oral lesions of various types have been reported with PR, including erythematous plaques, hemorrhagic puncta, and ulcers.

Causes:

• PR is similar to infectious exanthems in that it occurs in clusters among contacts, has a seasonal predilection to spring and autumn, and has a low rate of recurrence (3%).

• No bacteria, virus, or fungus has been isolated as a definite causal agent, although HHV-6 and HH-7 may play a role.

• Drugs such as bismuth, barbiturates, captopril, gold, organic mercurials, methoxypromazine, metronidazole, D-penicillamine, isotretinoin, tripelennamine hydrochloride, ketotifen, and salvarsan have been implicated in causing drug-induced PR.

• Atopy, seborrheic dermatitis, acne vulgaris, and dandruff are more common in patients with PR than in control subjects.

DIFFERENTIALS

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Erythema Multiforme
Pityriasis Alba
Psoriasis
Syphilis
Tinea

Other Problems to be Considered:

Nummular eczema
Seborrheic dermatitis
Drug eruptions
Erythema dyschromicum perstans
Lichen planus
Lichenoid reactions
Pityriasis lichenoides
Kaposi sarcoma

WORKUP

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Lab Studies:

• No diagnostic blood test is available.

• Laboratory testing is usually unnecessary; however, a rapid plasma reagin (RPR) test should be drawn, as PR can be confused with secondary syphilis.

• Blood profiles are normal; however, leucocytosis, neutrophilia, basophilia, and lymphocytosis have been seen.

• Minimal increases in the erythrocyte sedimentation rate (ESR), total protein, albumin, alpha1-globulin, and alpha2-globulin have been noted.

• Test findings for rheumatoid factor (RF), cold agglutinins, and cryoglobulins have been normal.

Procedures:

• A skin biopsy may be needed to diagnose pityriasis rosea (PR).

• The characteristic finding in PR is patchy keratosis and multinucleated giant cells.

• The granular cell layer is reduced or absent.

• Slight acanthosis and spongiosis may be present.

• Microscopic vesicles may be present in a clinically dry lesion.

• Superficial perivascular infiltration by lymphocytes, histiocytes and, rarely, eosinophils is present.

• Extravasated red blood cells (RBCs) may be seen in the papillae and epidermis.

TREATMENT

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Emergency Department Care:

• There is no need for treatment in the majority of cases for this self-limited condition. In one study, the use of erythromycin in patients older than age 2 years with PR has been shown to be useful.

• There is no reason to exclude children with PR from school.

Consultations: Consultation with a pediatric dermatologist may be required for atypical presentations of PR.

MEDICATION

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PR is a self-limited disease, and treatment is supportive. Water, sweat, and soap may cause irritation and should be avoided early in the disease. Topical zinc oxide and calamine lotion are useful for pruritus. If the disease is severe or widespread (eg, vesicular PR), topical or oral steroids may be used. Ultraviolet radiation therapy has been demonstrated to be effective for PR but may leave postinflammatory pigmentation at the site of the PR lesion.

Drug Category: Corticosteroids -- Have anti-inflammatory properties and cause profound and varied metabolic effects. Modify the body's immune response to diverse stimuli.

Drug Name	Prednisone (Deltasone, Meticorten, Orasone) -- May decrease inflammation by reversing increased capillary permeability and suppressing PMN activity.
Adult Dose	5-60 mg/d PO qd or divided bid/qid; taper over 2 wk as symptoms resolve
Pediatric Dose	4-5 mg/m2/d PO; alternatively, 0.05-2 mg/kg PO divided bid/qid; taper over 2 wk as symptoms resolve
Contraindications	Documented hypersensitivity; viral infection, peptic ulcer disease, hepatic dysfunction, connective tissue infections, and fungal or tubercular skin infections; GI disease
Interactions	Coadministration with estrogens may decrease prednisone clearance; concurrent use with digoxin may cause digitalis toxicity secondary to hypokalemia; phenobarbital, phenytoin, and rifampin may increase metabolism of glucocorticoids (consider increasing maintenance dose); monitor for hypokalemia with coadministration of diuretics
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Abrupt discontinuation of glucocorticoids may cause adrenal crisis; hyperglycemia, edema, osteonecrosis, myopathy, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, myasthenia gravis, growth suppression, and infections may occur with glucocorticoid use

Drug Name	Hydrocortisone (Cortaid, Cortef, Hycort) -- Adrenocorticosteroid derivative suitable for application to skin or external mucous membranes. Mineralocorticoid and glucocorticoid effects resulting in anti-inflammatory activity.
Adult Dose	Apply sparingly to affected areas bid/qid
Pediatric Dose	Administer as in adults
Contraindications	Documented hypersensitivity; viral, fungal, and bacterial skin infections
Interactions	None reported
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Prolonged use, applying over large surface areas, application of potent steroids, and occlusive dressings may increase systemic absorption of corticosteroids and may cause Cushing syndrome, reversible HPA axis suppression, hyperglycemia, and glycosuria

Drug Category: Antibiotics -- Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.

Drug Name	Erythromycin (E.E.S., E-Mycin, Eryc, Ery-Tab) -- Inhibits bacterial growth, possibly by blocking dissociation of peptidyl t-RNA from ribosomes and causing RNA-dependent protein synthesis to arrest. In children, age, weight, and severity of infection determine proper dosage. When bid dosing is desired, half-total daily dose may be taken q12h. May have anti-inflammatory and immunomodulatory effects.
Adult Dose	250 mg erythromycin stearate/base (or 400 mg ethylsuccinate) PO 1 h ac q6h, or 500 mg q12h Alternatively, 333 mg PO q8h; increase to 4 g/d depending on severity of infection
Pediatric Dose	30-50 mg/kg/d (15-25 mg/lb/d) PO divided q6-8h; double dose for severe infection
Contraindications	Documented hypersensitivity, hepatic impairment
Interactions	Coadministration may increase toxicity of theophylline, digoxin, carbamazepine, and cyclosporine; may potentiate anticoagulant effects of warfarin; coadministration with lovastatin and simvastatin, increases risk of rhabdomyolysis; decreases metabolism of repaglinide, thus increasing serum levels and effects
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Caution in liver disease; estolate formulation may cause cholestatic jaundice; GI side effects are common (give doses pc); discontinue use if nausea, vomiting, malaise, abdominal colic, or fever occur

FOLLOW-UP

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In/Out Patient Meds:

• A mild topical steroid or an emollient with 0.25% menthol may relieve the itching.

• Oral antipruritics may be helpful.

• Ultraviolet B therapy may be used to hasten resolution of the rash.

• Oral erythromycin has been used with success in one study in patients with PR over 2 years of age.

Prognosis:

• The prognosis of PR is excellent.

• Fewer than 3% of affected individuals experience recurrences.

Patient Education:

• The long duration of PR must be explained to patients and their families.

• The secondary rash develops over 2 weeks, persists for another 2 weeks, and then fades over another 2 weeks.

• Some lesions have persisted for as long as 3-4 months.

MISCELLANEOUS

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Medical/Legal Pitfalls:

• Other treatable conditions (eg, syphilis) may be missed if not considered.

TEST QUESTIONS

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CME Question 1: Which of the following is not likely to be confused with lesions of pityriasis rosea?

A: Tinea corporis
B: Nummular eczema
C: Pyogenic granuloma
D: Drug eruptions
E: Secondary syphilis

The correct answer is C: Pityriasis rosea lesions can be confused with lesions of secondary syphilis, tinea corporis and versicolor, nummular eczema, drug eruptions, and guttate psoriasis.

CME Question 2: What lesion is frequently seen prior to the rash of pityriasis rosea?

A: Vesicle on an erythematous base
B: Petechiae
C: Herald patch
D: Sentinel papule
E: Pyogenic granuloma

The correct answer is C: The herald patch in pityriasis rosea may be as large as 10 cm in diameter and is most frequently found on the trunk. The prevalence varies, but it is a common finding seen before the onset of the diffuse rash.

Pearl Question 1 (T/F): Pityriasis rosea (PR) is caused by Streptococcus pyogenes.

The correct answer is False: The cause of PR is unknown. It is believed to be the result of an infectious process, most likely viral, because of the presence of small epidemics and family outbreaks.

Pearl Question 2 (T/F): The most common site for lesions of pityriasis rosea (PR) is the trunk.

The correct answer is True: Lesions of PR most commonly occur on the trunk. Involvement is maximal over the abdomen and anterior and dorsal surfaces of the thorax. The secondary lesions appear as the primary patch in miniature, with the two red zones separated by the scaling ring. They are distributed in a Christmas tree pattern with their long axes following the lines of cleavage of the skin.

Pearl Question 3 (T/F): Typical configuration of the scales in pityriasis rosea is in a Christmas tree pattern.

The correct answer is True: Plaques are arranged with their long axes following skin cleavage lines; this creates a pine-bough, fir tree, or Christmas tree configuration.

Pearl Question 4 (T/F): Infants are more likely than older children to develop pityriasis rosea (PR).

The correct answer is False: PR has been described in infants as young as 3 months; however, it most commonly is seen in children and young adults aged 15-40 years.

BIBLIOGRAPHY

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• Chuh A, Chan H, Zawar V: Pityriasis rosea--evidence for and against an infectious aetiology. Epidemiol Infect 2004 Jun; 132(3): 381-90[Medline].
• Chuh A, Lee A, Zawar V: Pityriasis rosea--an update. Indian J Dermatol Venereol Leprol 2005 Sep-Oct; 71(5): 311-5[Medline].
• Coustou D, Leaute-Labreze C, Bioulac-Sage P, et al: Asymmetric periflexural exanthem of childhood: a clinical, pathologic, and epidemiologic prospective study. Arch Dermatol 1999 Jul; 135(7): 799-803[Medline].
• Drago F, Ranieri E, Malaguti F: Human herpesvirus 7 in patients with pityriasis rosea. Electron microscopy investigations and polymerase chain reaction in mononuclear cells, plasma and skin. Dermatology 1997; 195(4): 374-8[Medline].
• Hartley AH: Pityriasis rosea. Pediatr Rev 1999 Aug; 20(8): 266-9, quiz 270[Medline].
• Horio T: Skin disorders that improve by exposure to sunlight. Clin Dermatol 1998 Jan-Feb; 16(1): 59-65[Medline].
• Kay MH, Rapini RP, Fritz KA: Oral lesions in pityriasis rosea. Arch Dermatol 1985 Nov; 121(11): 1449-51[Medline].
• Kempf W, Burg G: Pityriasis rosea--a virus-induced skin disease? An update. Arch Virol 2000; 145(8): 1509-20[Medline].
• Nanda A, Al-Hasawi F, Alsaleh QA: A prospective survey of pediatric dermatology clinic patients in Kuwait: an analysis of 10,000 cases. Pediatr Dermatol 1999 Jan-Feb; 16(1): 6-11[Medline].
• Pomeranz AJ, Fairley JA: The systematic evaluation of the skin in children. Pediatr Clin North Am 1998 Feb; 45(1): 49-63[Medline].
• Scott LA, Stine MS: Pityriasis Rosea.
• Sharma PK, Yadav TP, Gautam RK: Erythromycin in pityriasis rosea: A double-blind, placebo-controlled clinical trial. J Am Acad Dermatol 2000 Feb; 42(2 Pt 1): 241-4[Medline].
• Wyndham M: Pityriasis. Practitioner 1997 Jun; 241(1575): 358[Medline].

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