Approach Considerations
Pityriasis rosea (PR) is a self-limited disease; 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 pityriasis rosea), topical or oral steroids may be used. Ultraviolet (UV) radiation therapy has been demonstrated to be effective for pityriasis rosea but may leave postinflammatory pigmentation at the site of the pityriasis rosea lesion. [59]
For patients in whom superficial tinea infection is a concern or possibility, topical antifungal therapy can be used. Some data suggest that the antiviral agent acyclovir could hasten resolution. [60, 61]
No restriction of activity or isolation is necessary. No evidence suggests that children with pityriasis rosea should be prevented from attending school.
Pharmacologic Therapy and Phototherapy
In most cases, it is not necessary to treat pityriasis rosea (PR). [62] The rash usually disappears in a few weeks, with no sequelae. Although various treatments have been attempted, the efficacy of most of them has not been definitively proved. [63]
Generally, patient education (eg, to avoid exposure to irritant agents [eg, harsh soaps, fragrances, hot water, wool, and synthetic fabrics], tight clothing, and scratching), coupled with reassurance that the rash will resolve, is all that is needed. However, it can be helpful to institute measures aimed at relieving bothersome symptoms (eg, pruritus).
Pruritus is commonly associated with pityriasis rosea and often responds to bland emollients, oral antihistamines, or topical preparations containing calamine, menthol-phenol, pramoxine, colloidal starch, or oatmeal. If the rash is severe, topical steroids can be applied. It must be kept in mind that although steroids alleviate the pruritus, they do not modify the eruption. The sedative effect of the antihistamines may help the patient to sleep better at night.
Systemic steroids are not recommended because they may exacerbate the disease. However, some dermatologists use prednisone (0.5-1 mg/kg/day for 7 days) in selected patients with severe pruritus, vesicular lesions, or the potential for significant postinflammatory hyperpigmentation, to suppress both pruritus and the exanthem. A double-blind, randomized, placebo-controlled trial evaluated short-course, low-dose oral prednisolone and suggested its use only for those with extensive high symptomatic pityriasis rosea. [64]
UV-B phototherapy, starting at 80% of the minimum erythrogenic dose, may rapidly relieve pruritus in resistant cases. [59] If itching is not controlled, the dose should be increased by 20% until symptoms decrease. However, one study failed to find improvement in pruritus with UV-B light therapy but did note decreased lesion severity. The possibility of postinflammatory pigmentation with light therapy must be kept in mind. [65, 66] An alternative approach is to administer low-dose UV-A1 phototherapy 2-3 times a week until resolution. [67]
In an atypical case of vesicular pityriasis rosea, considerable improvement was noted with the administration of 20 mg of dapsone twice daily. [49]
Some evidence suggests that acyclovir may be useful. 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 and may be of benefit. [68, 69] Lower dosages of 400 mg 5 times a day for 1 week may be equally effective. [60] However, acyclovir has been shown to be ineffective against HHV-6 and HHV-7. [68]
A number of antibiotics have been tried, without much success. 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 led to early resolution of symptoms. [70] However, another study did not find erythromycin to be useful in this condition. [71] Azithromycin also was not found to be effective for children with pityriasis rosea. [72]
In a randomized trial involving 42 patients with a clinical diagnosis of pityriasis rosea who were treated with either high-dose oral acyclovir or standard-dose oral erythromycin, all of the patients in the 2 groups exhibited a complete response after 8 weeks. [73] Although the study findings indicated that both agents were helpful, patients receiving acyclovir showed a better response, which was statistically significant in weeks 1, 2, 4, and 6.
Management of pityriasis rosea in patients with evidence of group A streptococcal infection may be warranted. The possible risk of scarlet fever and poststreptococcal sequelae should be considered. [74]
Consultations
Consultation with a dermatologist is warranted for patients with severe pruritus or disease that necessitates systemic steroid therapy, patients who desire UV-B therapy, or patients with atypical presentations of pityriasis rosea (PR).
Consultation with an infectious disease specialist should be considered for individuals with immunosuppression, such as recipients of solid organ transplants or hematopoietic stem cell transplants.
Pregnant women with pityriasis rosea should be referred to a high-risk maternal-fetal medicine specialist.
Long-Term Monitoring
Generally, pityriasis rosea (PR) resolves within 12 weeks, and no follow-up is necessary in most cases. However, follow-up care may be provided to ensure that the rash is improving. Patients with moderate-to-severe pruritus who are receiving topical steroids should be followed up by phone or in a return visit in 1-2 weeks.
Most cases of pityriasis rosea do not recur, [75] but some patients may develop the condition more than once, in which event alternative diagnoses or immune suppression should be considered. If the diagnosis is in doubt or if the disease persists past the expected duration period, further evaluation is advised. Pityriasis rosea that has persisted for longer than 3 months is often better classified as pityriasis lichenoides chronica.
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Herald patch. Image courtesy of Drexel Department of Dermatology slide collection.
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Christmas tree distribution of lesions on trunk. Image courtesy of Drexel Department of Dermatology slide collection.
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Histopathologic features of pityriasis rosea. Image courtesy of Gary R Kantor, MD, Department of Dermatology, Drexel University, Philadelphia, PA.