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Pieter-Jan Coenraads

Publications and source records attributed to Pieter-Jan Coenraads.

6 recordsLinked to original sources
PubMed2005

MnSOD polymorphisms in sensitized patients with delayed-type hypersensitivity reactions to the chemical allergen para-phenylene diamine: a case-control study.

Dyes such as para-phenylene diamine (PPD) or related para-compounds are very common contact sensitizers in man. The corresponding contact dermatitis in sensitized individuals is a complex and common illness associated with considerable morbidity and social cost. It has been found that oxidative stress from reactive oxygen species (ROS) may play an important role in the pre-immunological phase of allergic contact dermatitis to PPD. Manganese superoxide dismutase (MnSOD) is one of the primary enzymes that directly scavenge potential harmful oxidizing species. A valine (Val) to alanine (Ala) substitution at amino acid -9, occurring in the MnSOD gene, has been associated with various disease risk. The aim of our study was to investigate possible associations of the MnSOD 47 T>C genotype in exon 2 (Ala-9Val) and the 339 T>C genotype in exon 3 (Ile58Thr) with contact sensitization to PPD in humans in a case-control study. The study was performed in 157 unrelated cases and 201 age- and gender-matched controls. The MnSOD genotypes were determined using LightCycler allele discrimination assays. No heterozygous (CT) or homozygous carriers (TT) for the Ile58Thr polymorphism were found. The frequency for the C allele of the Ala-9Val polymorphism was 51% (79/157) in cases and 49% (107/201) in controls. Homozygous CC carriers (Ala/Ala) were 27% (43/157) in cases and 23% (46/201) in controls (odds ratio [OR], 1.3; 95% confidence interval [CI], 0.8-2.1). Stratification into subgroups based on gender and age limited the association to females. Increased risk among homozygous CC carriers (Ala/Ala) was only found in the group of older females (over 45 years, 25% versus 18%; OR, 1.5; 95% CI, 0.7-2.34). These data suggest that the C (Ala) allele of MnSOD modifies contact dermatitis risk among older females, but is not an independent susceptibility factor for contact sensitization to PPD.

Adolescent↗
PubMed2005

Chloracne.

Explore the source record for details and available documents.

Acne Vulgaris↗
PubMed2004

Comparison of oral psoralen-UV-A with a portable tanning unit at home vs hospital-administered bath psoralen-UV-A in patients with chronic hand eczema: an open-label randomized controlled trial of efficacy.

OBJECTIVE: To study whether oral psoralen-UV-A (PUVA) with a portable tanning unit at home is as effective as hospital-administered bath PUVA in patients with chronic hand eczema. DESIGN: Open-label randomized controlled trial, with a 10-week treatment period and an 8-week follow-up period. SETTING: Two university hospital dermatology departments in the Netherlands, specializing in hand eczema. PATIENTS: One hundred fifty-eight patients with moderate to severe chronic hand eczema (more than 1 year in duration). INTERVENTIONS: Oral PUVA using methoxsalen capsules and a simple portable commercial facial tanning unit, or hospital-administered bath PUVA with trioxsalen. MAIN OUTCOME MEASURES: The primary outcome was clinical assessment by a hand eczema score (evaluation of desquamation, erythema, vesiculation, infiltration, fissures, itch, and pain, each on a 4-point scale) after 10 weeks of treatment. The secondary outcome was hand eczema score at 8 weeks of follow-up, after completion of treatment. The tertiary outcome was travel cost and time off work. RESULTS: Both groups showed a comparable and substantial decrease in hand eczema score (meaningful clinical improvement). This decrease was maintained during the follow-up period. Patients treated with oral PUVA at home had lower travel costs and less time off work. CONCLUSIONS: Oral PUVA at home has a clinically relevant efficacy, similar to that of hospital-administered bath PUVA. This effect was maintained during an 8-week follow-up period. It resulted in lower travel costs and less time off work.

Administration, Oral↗
PubMed2003

Evidence-based diagnosis in patch testing.

Evidence-based medicine (EBM) is defined as the integration of the best research evidence with clinical expertise and patient values. Based on the principles of EBM, we can conclude that patch testing is cost-effective only if patients are selected on the basis of a clear-cut clinical suspicion of contact allergy and only if patients are tested with chemicals relevant to the problem (high pretest probability). Random patch testing (low pretest probability) should be discouraged. Proper pretest probability assessment can only be done in expert centres, because problem-based testing requires both a thorough knowledge of the patch-test procedure and knowledge about potential sensitizers in a specific environment.

Allergens↗
PubMed2003

Randomized clinical trials for psoriasis 1977-2000: the EDEN survey.

This study aims to describe the range of treatment comparisons, study designs and quality of reporting of randomized clinical trials (RCTs) in psoriasis published in a variety of medical and dermatological journals, and to analyze time trends with quality items. Hand-searching of clinical trials of psoriasis published from 1977 to 2000 in 13 medical or dermatological journals, selected as relevant to a European readership, was performed. A total of 249 trials published in 226 papers were classified as RCTs. Of these, 139 (55.8%) employed a parallel control group design, 107 (43.0%) studies adopted a self-control design and 3 (1.2%) a cross-over design. The median number of patients recruited per study was 40 (range 6-699). Overall, 55 different treatment modalities, including topical, ultraviolet-based, systemic, and other miscellaneous therapies were assessed. Only 31 (12.5%) RCTs were comparative studies of treatment modalities in different therapeutic classes. Most of the studies were short-term with a median study duration of 7 weeks (range 1-104), with only 18 studies (7.2%) lasting for more than four months. A variety of outcome measures including 44 different score systems were employed. According to the conclusions of the authors, 196 (78.7%) studies were judged to provide striking or definite observations in favor of one of the treatments examined. No important variations over time were documented for quality items. Based on our survey we have identified an enormous range of treatments that have been evaluated for psoriasis over the examined period. Most studies were short-term, and only a handful compared treatment options in different therapeutic classes. Since we did not examine all the relevant journals, the number of treatment options may be even greater than we have documented. There is an urgent need to reset the research agenda focusing on long-term comparative RCTs. Editors of major medical and dermatological journals are urged to take a role in improving the quality of RCT reporting.

Clinical Trials as Topic↗