Clinical studies on patients with pityriasis rosea
Clinical Studies on Patients with Pityriasis Rosea submitted by
Chuh An Tung Antonio for the degree of Doctor of Medicine at the University of Hong Kong
in October 2003
The aim of this thesis is to investigate the epidemiology, aetiology, clinical features, and quality of life (QOL) of patients with pityriasis rosea (PR).
I reported a qualitative study analysing the rash orientation. Describing such as following Langer's cleavage lines was found to be the most precise and accurate. The application of digital epiluminescence dermatoscopy to identify peripheral collarette scaling was described. I presented two patients with atypical PRo I reported a prospective case control study of 15 patients with PR and 58 control subjects and attempted an initial validation study on a set of diagnostic criteria.
I reported a study analysing for temporal case clustering of PR in Hong Kong. Significant clustering independent of seasonal variation was observed. I confirmed my findings on 1379 patients with PR in Kuwait, Turkey and Minnesota.
I reported prospective case control studies investigating the association between PR and human herpesvirus 6 (lllIV -6), lllIV -7 (15 patients and 15 age-and-sex pair-
matched controls, cytomegalovirus, Epstein-Barr virus, parvovirus B19, Chlamydia pneumoniae, C. trachomatis, Legionella longbeachae, L. micdadei, L. pneumophila, and Mycoplasma pneumoniae (13 patients and 13 paired controls) infections. Polymerase chain reaction was employed to detect lllIV -6 and lllIV -7 DNA in plasma and peripheral blood mononuclear cells (PBMC), cytomegalovirus DNA in plasma and Epstein-Barr virus DNA in PBMC. Serology was done for all viruses and bacteria investigated. No evidence of active infection by these organisms was found.
I reported a study investigating the association of PR with autoimmune markers on 18 patients with PR and 18 controls. Significantly more patients with PR were found to have positive autoimmune markers.
I presented a study investigating the QOL in patients with PR, and whether such is related to rash severity. I constructed a valid and reliable Dermatology Life Quality Index Cantonese version. 22 patients with PR and 22 age-and-sex-matched controls with atopic dermatitis and acne vulgaris were recruited. QOL of patients with PR was significantly less affected than patients with atopic dermatitis, but insignificantly different from patients with acne vulgaris. Effects on QOL in PR were insignificantly correlated with rash severity.
I reported a study investigating the effects on QOL in children with PR and the concerns of their parents. I constructed a valid and reliable Children Dermatology Life Quality Index Cantonese version. QOL of ten children with PR was observed to be significantly less affected than ten children with atopic dermatitis, and
significantly more affected than ten children with no active skin problem. The major concerns of parents were the aetiology, infectivity, relapse and complications.
The significance of these findings is that although temporal case clustering in PR is supportive of an infectious aetiology, a specific organism has not been identified. Further studies to identify such agent are warranted. Physicians might apply digital epiluminescence dermatoscopy and the set of diagnostic criteria to assist in diagnosis. They should bear in mind that unlike atopic dermatitis and acne vulgaris, rash severity in PR is not directly correlated to effects on QOL, and treatment should be tailored to the individual patient.
School:The University of Hong Kong
School Location:China - Hong Kong SAR
Source Type:Master's Thesis
Keywords:pityriasis rose epidemiology etiology patients quality of life
Date of Publication:01/01/2003