Chua, Ser Ling
(2015)
Papular pruritic eruption of human immunodeficiency virus infection.
PhD thesis, University of Nottingham.
Abstract
Background
Papular pruritic eruption (PPE) of human immunodeficiency virus (HIV) infection is common HIV-infected populations who live in tropical and subtropical regions. It is characterized by chronic and intensely itchy papules that are usually more highly concentrated on the extremities, adversely impacting on quality of life. Its aetiology has been postulated to be an altered and exaggerated immunological response to insect bites or stings. It has been reported to diminish in severity or resolve with antiretroviral therapy (ART). Its presence after at least six months of ART has been proposed as one of several clinical markers of failure of antiretroviral treatment.
Objectives
1. To systematically summarise the evidence of interventions for PPE
2. To translate, culturally adapt, and test oral administration of a Runyankore-version of Skindex-16 for use in dermatology research in Mbarara, Uganda
3. To determine factors associated with PPE in HIV-infected Ugandan adults receiving ART for at least 15 months
4. To describe the natural history of PPE in HIV-infected Ugandan adults over two years from the time of ART initiation and explore the association between recurrent or persistent PPE and antiretroviral treatment failure
Methods
Systematic review of interventions for PPE
Electronic searches of Medical Literature Analysis And Retrieval System Online (Medline), Excerpta Medica Database (Embase), Cumulative Index To Nursing And Allied Health Literature (CINAHL), Global Health Library, Cochrane Library, World Health Organization (WHO) International Clinical trials registry and National Library Of Medicine (NLM) gateway were carried out from January 1980 to July 2014. Studies of any design were included. The primary outcome measure for this review was resolution of skin disease. The quality of evidence was assessed using the Newcastle-Ottawa quality assessment scale and Grading Of Recommendation, Assessment, Development And Evaluation (GRADE) approach, where appropriate. Two authors carried out data extraction and quality assessment of studies independently.
Runyankore-version of Skindex-16 for oral administration in Mbarara, Uganda
Skindex-16 in English was translated to Runyankore, and then back-translated to English. The original and back-translated versions of Skindex-16 were compared for fidelity of translation. The Runyankore-version was administered orally to 47 dermatology patients and 47 random hospital visitors. Study participants were also asked about the characteristics of their skin condition including its duration, presence of skin colour change and ease or difficulty of concealment as well as an open question on how their skin condition has affected them.
Case control study examining factors associated with PPE in the ART era
This is a case–control study nested within a 515-person cohort receiving care at the HIV clinic of a teaching hospital in Mbarara, Uganda. Forty-five cases and 90 controls were enrolled. Cases had received ART for ≥15 months, fulfilled the clinical case definition of PPE and had skin biopsy findings consistent with PPE. Each case was individually matched with two controls for age, sex and ART duration.
Cohort study describing the natural history of PPE over two years from ART initiation
This is a cohort study of HIV-infected Uganda adults initiating ART and receiving care at the HIV clinic of a teaching hospital in Mbarara, Uganda who fulfilled the clinical case definition of PPE and had skin biopsy findings consistent with PPE. Standardised interviews, clinical photography, HIV viral load, CD4 counts and CD8+ T-cell activation markers were measured at three-month intervals for two years.
Results
Systematic review of interventions for PPE
No randomised controlled trials were identified. Thirteen studies with a total 188 participants were included. ART was associated with resolution of PPE in a prospective observational study that had high loss to follow-up rates. Two observational studies reported positive responses of PPE to oral antihistamines (promethazine and cetirizine). Pentoxifylline was associated with diminished signs and symptoms of PPE in an uncontrolled open trial and superior to dapsone and a combination of antihistamine and topical corticosteroids in a parallel group non-randomised trial. Resolution of PPE was reported with a combination of topical corticosteroids and oral antihistamines in a case report. The efficacy of ultraviolet B (UVB) phototherapy was reported in an observational study with eight participants and three case studies with a total of five participants.
Runyankore-version of Skindex-16 for oral administration in Mbarara, Uganda
Oral delivery was feasible, taking ≤10 minutes per subject. High Cronbach α values (0.86, 0.88 and 0.85 for Symptoms, Emotions and Functioning subscales, respectively) demonstrated internal consistency reliability. As hypothesised, subjects with reported skin problems, dyspigmentation and difficulty in concealment had higher mean Skindex-16 scores, indicating construct validity. A large proportion (72.4%) of responses to the open-ended question were addressed in Skindex-16, indicating content validity.
Case control study examining factors associated with PPE in the ART era
Twenty-five of 45 cases (56%) had histological findings consistent with PPE (known as PPE cases). At skin examination and biopsy (study enrolment), a similar proportion of PPE cases and their matched controls had plasma HIV RNA <400 copies/ml (96% vs. 85%, p=0·31). The odds of having PPE increased four-fold with every log increase in viral load at ART initiation (p=0.02) but not at study enrolment. CD4 counts at ART initiation and study enrolment, and CD4 gains and CD8 T-cell activation measured 6 and 12 months after ART commencement were not associated with the presence of PPE. Study participants who reported daily insect bites had greater odds of being cases [odds ratio (OR) 8.3, p<0.001] or PPE cases (OR 8.6, p=0.01).
Cohort study of natural history of PPE over 2 years from ART initiation
Seventeen (15 female and 2 male) participants with a median age of 29.8 years were enrolled. Median CD4 count and HIV viral load at ART commencement was 108 cells/mm3 and 114,442 copies/ml, respectively. Resolution of PPE occurred in 13 of 17 (76%) study participants at a median time of 8.5 months after ART initiation, although PPE recurrence was observed at seven participants during the study period. Two participants had persistent PPE. Virological failure was not detected in any study participant. HIV RNA was less than 400 copies/ml at a median time of three months from ART initiation in all study participants.
Conclusions
1. The evidence base of interventions for PPE is of low quality. There is some evidence of the efficacy of ART in the management of PPE. Pentoxifylline and phototherapy may have a role in its management but are unlikely to be available in resource-limited settings. Oral antihistamines and topical corticosteroids may be helpful in some individuals affected by PPE.
2. The orally administered Runyankore-version of Skindex-16 is reliable, with construct and content validity, and feasible for use in dermatology research in Mbarara, Uganda.
3. PPE in HIV-infected Ugandan adults receiving ART for at least 15 months was associated with reported daily insect bites and greater HIV viraemia at ART commencement, independent of CD4 count.
4. Recurrent or persistent PPE in HIV-infected Ugandan adults observed over two years from initiation of ART was not associated with virological failure in participants of this study.
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