Para-phenylenediamine (PPD) and para-aminoazobenzene are strong sensitizers. By the patch test procedure, the patient may be sensitized to these agents. Combined testing of para-compounds may increase the risk of active sensitization. We studied the % of positive patch test reactions and their relevance. In order to assess the risk of active sensitization, we compared the % of relevant reactions of both early (2/3 days) and late (7 days) reactions. We also compared the percentage of positive patch test reactions to PPD and their relevance if simultaneously tested with para-aminoazobenzene. We studied the patch test reactions to PPD in the routine series in 2058 patients. In a group of 678 patients we tested PPD and para-aminoazobenzene simultaneously. 4.3% and 3.1% of the patients reacted to PPD, respectively, with and without simultaneous testing with para-aminoazobenzene. We estimated the reactions as relevant in 21.1% and 39.7%, respectively, with and without simultaneous testing with para-aminoazobenzene. We considered none of the late reactions as relevant. We found a high proportion of relevant patch test reactions to PPD, but sensitization to PPD by the patch test procedure is a risk. We state that routine series should not contain PPD. The high number of irrelevant late positive reactions strongly suggests active sensitization. Moreover, PPD is not a ubiquitous allergen and can be tested on a non-routine basis if industrial exposure to para-compounds is suspected or if a specific localization (e.g., head or feet) prompts the testing of PPD. Testing PPD combined with para-aminoazobenzene does lead to a slight increase in positive reactions to PPD (p<0.25) and to an increase in irrelevant reactions (p<0.10).

Our results clearly show that P. ovale-specific IgE is strongly related to the head and neck localization of atopic dermatitis, but RAST seems more sensitive than a prick test with the extract we used.

While solar protection has become part of routine beach behavior, there is room for improvement by more frequent application of sunscreen cream, the use of a higher sun protection factor (SPF) (15+), timed sunbathing, more use of clothing and hats and more seeking of shade. The results of this study can assist in evaluating the effectiveness of current sun-protection campaigns and health education programs.

Public health campaigns encourage people to protect themselves against skin cancer by using sunscreens and taking other protective measures. The objective is to estimate the impact of these campaigns on the rise of awareness among the general public. This study explores the prevalence and predictors of solar protection behaviour in a sample of beachgoers and compares these results to another similar study carried out 9 years earlier (i.e. summer 2001). During the month of August 2010, a total of 408 participants (144 men and 264 women) were randomly selected on their way to the Belgian beach in the city of Ostend, Belgium. The solar protection behaviour of each participant was assessed by direct observation and an interview. The exact same questions were asked as in 2001. The general risk awareness stays the same for skin aging and skin cancer but gets higher for sunburn. When we control these results for sex, the overall higher general awareness is completely because of the higher awareness of the female subgroup. As in 2001, risk awareness is considerably higher in the female subgroup than in the male one. As in 2001, sunscreen cream was the most popular preventive behaviour in 2010 (use of sunscreen with sun protection factor 15 or higher reported by 66.4%), followed by timed sun exposure (46.8%), use of clothing and hats (36.8%) and shade (34.1%). As in summer 2001 the sunscreen use is more popular in the female population. The use of protective clothing and hats is more popular in the male group. As solar protection has become part of the beach behaviour routine, there is room for improvement for their more frequent application, the use of a higher sun protection factor (15+), timed sunbathing, more use of clothing and hats and seeking shade. The results of this study can assist in evaluating the effectiveness of present sun-protection campaigns and health education programmes.

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.