Pityriasis rosea: a clinicoepidemiological study of 115 cases

INTRODUCTION

Pityriasis rosea (PR) is a skin eruption of unknown etiology, probably related to human herpes virus-7 (HHV-7).¹ In most cases the patients present with a primary lesion known as herald patch followed by multiple small lesions. Apart from this classic type, various atypical types are also described in literature. In this study the prevalence of various clinical patterns of PR and their epidemiological features in patients attending the dermatology outpatient department were analysed.

METHODS

A prospective study of clinicoepidemiological features in 115 patients with PR who attended the dermatology outpatient department of Kannur Medical College, Anjarakandy was done. The study was done over a period of one year from May 2016 to April 2017 after getting institutional ethical clearance.

All cases were subjected to potassium hydroxide (Koh) mount examination to rule out fungal infection. Inclusion criteria: All patients with clinically diagnosed PR who were willing for the study were included. Exclusion criteria: Patients who were Koh mount and/or VDRL positive, with features of seborrheic dermatitis, inconclusive diagnosis or not willing for the study were excluded. Various factors like age, gender, symptoms, prodromal features, clinical pattern and history of drug intake were noted. Patients were examined every two weeks until remission. They were prescribed calamine lotion and antihistamines.

RESULTS

Age of the patients ranged from 16 months to 62 years. Out of the 115 patients included in the study maximum cases were seen in young adults with male preponderance (Table 1). In this study a seasonal variation in PR cases were seen with maximum cases seen during the months of September and October (Table 2). Itching was present in about two third of the patients. History of preceding respiratory tract infection was seen in 6 cases. History of drug intake was present in 4 cases. Classical type of PR was seen in majority of cases. Atypical variants like absent herald patch, inverse PR, papular PR and localised PR were also seen (Table 3). Localised PR presented with lesions localised to face in 1 case and lesions over left side of neck and upper trunk in another case.

DISCUSSION

Pityriasis rosea is a self-limiting disorder with recent studies showing human herpes virus (HHV) 6 and 7 as the probable etiological agents. It begins as an erythematous scaly plaque known as herald patch, which is followed by an eruption of multiple small erythematous scaly lesions located predominantly on the trunk along the lines of skin cleavage. Various atypical presentations like absent or multiple herald patch, papular, vesicular, purpuric, erythema multiforme like, urticarial, lichenoid, giant PR, localised or atypical distribution can also occur.² It is commonly seen in young adults with both sexes being affected.^3,4 In our study males in the age group of 10 to 30 were commonly affected. Some studies have shown seasonal variation with cases occurring more frequently during winter and rainy season.^5,6 In our study maximum cases were seen during the months of September and October. It is usually asymptomatic but some cases known as PR irritata presents with severe itching. In our study most of the patients had mild to moderate itching and severe itching was noticed in 2 cases of papular variant. PR is a self-limiting disorder and it usually subsides in 2 to 8 weeks. Most of our cases (78%) lasted for 4 to 5 weeks. Various treatment options used include topical emollients, corticosteroids, macrolide antibiotics, antivirals like acyclovir and phototherapy.⁷

CONCLUSION

PR is a disorder seen commonly in young adults more often during winter season. Awareness about the self-limiting nature of the disease will help to reduce the distress and prevent unnecessary treatment.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the institutional ethics committee

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