Indian Journal of Dermatology
: 2010  |  Volume : 55  |  Issue : 3  |  Page : 246--248

The comparison between the efficacy of high dose acyclovir and erythromycin on the period and signs of pitiriasis rosea

Amirhooshang Ehsani1, Nafiseh Esmaily1, Pedram Noormohammadpour1, Siavash Toosi1, Alireza Hosseinpour1, Mahbobeh Hosseini2, Shima Sayanjali1,  
1 Department of Dermatology, Tehran University of Medical Sciences, Razi Hospital, Tehran, Iran
2 Department of Internal Medicine, Baquitallah University of Medical Sciences, Baquitallah Hospital, Tehran, Iran

Correspondence Address:
Pedram Noormohammadpour
Vahdate-eslami Sq., Vahdate-Eslami Ave., Razi Hospital, 11996, Tehran


Background: Pityriasis Rosea (PR) is an acute inflammatory and self-limiting skin disorder, sometimes with troublesome symptoms. To date, there are few treatments available for this disorder. Aim: Compare the traditional treatment with erythromycin to a newly introduced antiviral treatment acyclovir for PR. Materials and Methods: Patients with clinically confirmed diagnosis of PR, matching our exclusion criteria, were enrolled. They were randomized in two groups that received high-dose oral acyclovir or erythromycin. The participants were evaluated two, four, and eight weeks after commencement of the study and followed for one year. Results: A total of 30 patients including 15 males and 15 females completed the study. After eight weeks, 13 patients in the acyclovir group experienced complete response, while in the erythromycin group only six patients had complete response (P < 0.05). Also, patients in the acyclovir group experienced faster resolution of pruritus in comparison with the erythromycin group (not significant). No adverse drug reaction was detected in both groups. Conclusion: It seemed that a high-dose of oral acyclovir was a safe and effective therapy for PR, although this remained to be confirmed in larger studies.

How to cite this article:
Ehsani A, Esmaily N, Noormohammadpour P, Toosi S, Hosseinpour A, Hosseini M, Sayanjali S. The comparison between the efficacy of high dose acyclovir and erythromycin on the period and signs of pitiriasis rosea.Indian J Dermatol 2010;55:246-248

How to cite this URL:
Ehsani A, Esmaily N, Noormohammadpour P, Toosi S, Hosseinpour A, Hosseini M, Sayanjali S. The comparison between the efficacy of high dose acyclovir and erythromycin on the period and signs of pitiriasis rosea. Indian J Dermatol [serial online] 2010 [cited 2022 May 28 ];55:246-248
Available from:

Full Text


Pityriasis rosea (PR) is an acute inflammatory and self-limiting disease of the skin. It typically begins as a single thin oval scaly plaque called a herald patch, and is typically asymptomatic. [1] PR is common among patients visiting dermatologists. The incidence of PR varies from 0.39 [2] to 4.80 [3] per 100 dermatological patients. The prevalence of PR is estimated at approximately 0.6% between 10 and 29-year-old people, [4] with an Male/Female ratio of about 1/1.43. [5] There are a number of studies in favor of an infectious etiology for this disorder, [6],[7] and now it is believed that PR is induced by some of the Human Herpes Virus members, mainly HHV7 and HHV6. [8],[9],[10] Oral erythromycin is reported to be of benefit to patients with PR, [11] although recent clinical experiences suggest that the use of macrolids including erythromycin and azithromycin are of no value in the treatment of PR. [12],[13],[14] Recent studies are focused on using antiviral agents in this disorder, mainly acyclovir. [15] According to this study, it seems that acyclovir is an effective and safe therapy for treating PR. We were unable to find a study comparing these two drugs. The aim of this study is to compare the efficacy of the traditional treatment with erythromycin and the recently introduced treatment with acyclovir.

 Materials and Methods

This randomized clinical trial was conducted for a period of one year from May 2007 to April 2008. Patients with diagnosis of PR, confirmed clinically by two academic dermatologists, were selected for the study, if they visited our clinic during the first week of their disease and if they had extensive generalized lesions. An informed consent was taken from each patient or parent for inclusion in the study. Patients were excluded if they were pregnant or breast feeding women, or had any history of sensitivity to acyclovir or erythromycin, and renal or hepatic impairment, or were suspected to have fungal infection, psoriasis, or eczema. Venereal Disease Research Laboratory (VDRL) test was performed on all patients and positive results were confirmed by the fluorescent treponemal antibody absorbed (FTA-ABS) test, to exclude second-stage syphilis. The patients were randomized in two groups, A and B. Group A received high-dose acyclovir (4 gr daily, in five divided doses, for 10 days) while group B received oral erythromycin (400 mg QID for 10 days). Acyclovir and erythromycin used in the study were in similar white pill forms, with the same packaging. The patients were visited two, four, and eight weeks after commencement of the study, to evaluate response to treatment and then followed for one year to detect any recurrences. They were evaluated for improvement in symptoms (mainly pruritus), appearance of new lesions or resolution of previous ones, and increase or decrease in erythema and scaling. Count of lesions on the body was documented on every visit, for further evaluation of response to treatment. The responses were categorized as:

Complete response: No new lesions followed by disappearing of all previous lesions, with or without residual post-lesional pigmentationPartial response: Few new lesions plus regression or disappearing of some previous lesionsNo response: No regression of lesions, along with appearance of new lesions.

Statistical analysis

Student t-test was used for comparing means, while the chi-square test was used for comparing differences in proportions wherever necessary. P < 0.05 was considered significant.


The participants in the study were 30 patients with PR, who passed our inclusion and exclusion criteria. The average age of the patients who attended this study was 32.9 ± 16 years; 15 (50%) female and 15 (50%) male.

Characteristics of the two groups

[Table 1] shows the demographic characteristics of the two groups. As shown in the table, there were no significant differences between them.{Table 1}

Six patients in the erythromycin group and eight patients in acyclovir group had pruritus before the commencement of the study.

Response to drugs

At the end of the study, in group A, which received high-dose acyclovir, 13 patients had complete response, while in group B, treated with erythromycin, only six patients had complete response (P < 0.05). [Table 2] shows the rate of response to the prescribed drugs in the two groups.{Table 2}

After eight weeks, in the patients treated with acyclovir, two had partial response, while in the erythromycin group, nine had partial response (P > 0.05). Pruritis is one of the most distressing symptoms of PR. As we can see, in group A, pruritus in all patients resolved after two weeks, while in group B two patients after four weeks and one patient after eight weeks had pruritus, although this was not significant.


In our study, the male to female ratio is about one in both treatment groups. None of our patients in both groups achieved complete response during the first two weeks of treatment. This is contrary to some other trials [11],[15],[16] that reported complete response after two weeks of treatment in their subjects. After eight weeks, the rate of complete response in patients who received high-dose acyclovir was significantly higher than their matches who received oral erythromycin. This is in agreement with the studies that reported the efficacy of acyclovir in treating PR [15] and questioned the effect of erythromycin in this disorder. [12],[13] Nowadays, there are increasing evidences toward confirming the role of the human herpes virus. [17],[18],[19] There is an important note to consider with regard to the effect of acyclovir on different herpes virus family members. To date, it has been seen that only high doses of acyclovir have had a suppressing effect on HHV-6 [20],[21],[22] and the same is correct about HHV-7. In fact HHV-7 is less sensitive to acyclovir than HHV-6. [23],[24] These studies have shown that antiviral drugs such as Cidofovir and Foscarnet [25],[26],[27] may be more effective against HHV-6, 7. Considering the high rate of side-effects of these drugs and according to the self-limiting nature of PR, in many cases we preferred to use high-dose acyclovir as a safer alternative, to evaluate it's effects on relieving the symptoms of PR. A significantly higher response to high-dose acyclovir in our study may be another clue to confirm the positive role of this drug in eliminating some manifestations of PR. According to a small number of patients included in our study and the clinical confirmation of PR diagnosis, we suggest further trials with a larger number of participants, and possibly a pathologically confirmed diagnosis of PR, to confirm our results. Acyclovir is probably a safe treatment in patients with PR according to their age range, but its efficacy must be confirmed in larger studies with higher sample sizes.


1Blauvelt A. Pityriasis rosea. In: Wolff K, Goldsmith l, Katz S, Gilchrest B, editors. Fitzparick's dermatology in general medicine. 7th ed. McGrawHill; 2008. p. 362-6.
2de Souza Sittart JA, Tayah M, Soares Z. Incidence pityriasis rosea of Gibert in the Dermatology Service of the Hospital do Servidor Publico in the state of Sao Paulo. Med Cutan Ibero Lat Am 1984;12:336-8.
3Olumide Y. Pityriasis rosea in Lagos. Int J Dermatol 1987;26:234-6.
4Traore A, Korsaga-Some N, Niamba P, Barro F, Sanou I, Drabo YJ. Pityriasis rosea in secondary schools in Ouagadougou, Burkina Faso. Ann Dermatol Venereol 2001;128:605-9.
5Chuh A, Lee A, Zawar V, Sciallis G, Kempf W. Pityriasis rosea: An update. Indian J Dermatol Venereol Leprol 2005;71:311-5.
6Case clustering in pityriasis rosea: Support for role of an infective agent. Br Med J (Clin Res Ed) 1982;284:977.
7Chuh AA, Lee A, Molinari N. Case clustering in pityriasis rosea: A multicenter epidemiologic study in primary care settings in Hong Kong. Arch Dermatol 2003;139:489-93.
8Drago F, Ranieri E, Malaguti F, Losi E, Rebora A. Human herpesvirus 7 in pityriasis rosea. Lancet 1997;349:1367-8.
9Broccolo 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 2005;124:1234-40.
10Watanabe 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 2002;119:793-7.
11Sharma PK, Yadav TP, Gautam RK, Taneja N, Satyanarayana L. Erythromycin in pityriasis rosea: A double-blind, placebo-controlled clinical trial. J Am Acad Dermatol 2000;42:241-4.
12Bukhari IA. Oral erythromycin is ineffective in the treatment of pityriasis rosea. J Drugs Dermatol 2008;7:625.
13Rasi A, Tajziehchi L, Savabi-Nasab S. Oral erythromycin is ineffective in the treatment of pityriasis rosea. J Drugs Dermatol 2008;7:35-8.
14Amer A, Fischer H. Azithromycin does not cure pityriasis rosea. Pediatrics 2006;117:1702-5.
15Drago F, Vecchio F, Rebora A. Use of high-dose acyclovir in pityriasis rosea. J Am Acad Dermatol 2006;54:82-5.
16Bigby M. A remarkable result of a double-masked, placebo-controlled trial of erythromycin in the treatment of pityriasis rosea. Arch Dermatol 2000;136:775-6.
17Chuh 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 2006;20:667-71.
18Chuh AA, Kempf W. The identification of primary human herpesvirus 7 infection in young adults with pityriasis rosea by investigating avidity of antibodies. J Eur Acad Dermatol Venereol 2006;20:629-30.
19Canpolat KB, Adisen E, Bozdayi G, Yucel A, Fidan I, Aksakal N, 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 2009;23:16-21.
20Amjad M, Gillespie MA, Carlson RM, Karim MR. Flow cytometric evaluation of antiviral agents against human herpesvirus 6. Microbiol Immunol 2001;45:233-40.
21Burns WH, Sandford GR. Susceptibility of human herpesvirus 6 to antivirals in vitro. J Infect Dis 1990;162:634-7.
22Reymen D, Naesens L, Balzarini J, Holy A, Dvorakova H, De CE. Antiviral activity of selected acyclic nucleoside analogues against human herpesvirus 6. Antiviral Res 1995;28:343-57.
23Yoshida M, Yamada M, Tsukazaki T, Chatterjee S, Lakeman FD, Nii S, et al. Comparison of antiviral compounds against human herpesvirus 6 and 7. Antiviral Res 1998;40:73-84.
24Zhang Y, Schols D, De CE. Selective activity of various antiviral compounds against HHV-7 infection. Antiviral Res 1999;43:23-35.
25Akhyani N, Fotheringham J, Yao K, Rashti F, Jacobson S. Efficacy of antiviral compounds in human herpesvirus-6-infected glial cells. J Neurovirol 2006;12:284-93.
26Johnston RE, Geretti AM, Prentice HG, Clark AD, Wheeler AC, Potter M, et al. HHV-6-related secondary graft failure following allogeneic bone marrow transplantation. Br J Haematol 1999;105:1041-3.
27Takahashi K. Recent advances in antiviral drugs-antiviral agents to HCMV, HHV-6, and HHV-7. Nippon Rinsho 1998;56:140-4.