Psoriasis in Australian twins

Abstract

PURPOSE:Appendicitis is an inflammation of the appendix, the etiology of which is still poorly understood. Previous studies have shown an increased risk for cigarette smokers but no accounts for the timing of exposure to smoking relative to appendectomy were made. METHODS: Based on questionnaire data, both cohort and co-twin case-control analyses were conducted to assess the effect of active cigarette smoking on appendectomy in 3808 Australian twin pairs. Smoking status was defined as a time-dependent covariate to account for differences in timing of smoking initiation and onset of appendicitis. RESULTS: The questionnaire had a 65% pairwise response rate. After controlling for sex, age, and year of birth, appendectomy risk in current smokers was statistically significantly increased by 65% relative to never-smokers. This was largely unchanged by the duration or intensity of smoking and was not affected by socioeconomic status or father's occupation. The effect was stronger in females. Among former smokers, increased time since quitting significantly reduced the odds ratio of appendectomy by 15% for every year since quitting. CONCLUSION: After adjustment for age and other confounders, there was an increase in risk of appendectomy among current smokers relative to never-smokers, particularly in females. This study adds to the body of knowledge on the effects of tobacco smoking on the gastrointestinal tract.

Improvement of Psoriasis after Tonsillectomy Is Associated with a Decrease in the Frequency of Circulating T Cells That Recognize Streptococcal Determinants and Homologous Skin Determinants

“…In this way IFN-g may play a major role in enhancing the IL-17 response (4). Psoriasis has a strong genetic component, with a 40-70% concordance in identical twins (7,8). Several susceptibility alleles have now been identified and confirmed (9), and HLA-Cw*0602 has recently been implicated as the strongest susceptibility allele in psoriasis (10).…”

Cancer risk in hospitalised psoriasis patients: a follow-up study in Sweden

“…Its prevalence in Western populations is estimated to be around 2 -3% (Gudjonsson and Elder, 2007). The cause of psoriasis is poorly understood, but is believed to include a genetic component (Brandrup et al, 1982;Duffy et al, 1993;Krueger and Ellis, 2005); concordance in monozygotic twins is about 70%, whereas in dizygotic twins this is only 20% (Krueger and Ellis, 2005). Psoriasis is an immune-mediated disorder, for which T cells are abnormally activated to release cytokines, which cause inflammation and rapid production of skin cells (Griffiths and Voorhees, 1996).…”

The prevalence of psoriasis among elderly individuals: more questions than answers

“…19 Yet other studies found leveling off or even drastically declining rates of psoriasis prevalence for individuals beyond the age of 70 years compared to younger age classes. 17,[21][22][23][24][25] Thus, in contrast to the relatively high prevalence measured herein, a nation-wide telephone survey in Spain applying essentially the same structured questionnaire recorded only 0.33% age-specific prevalence in persons >70 years old. This was only a quarter of the average psoriasis prevalence measured in the whole target population of this latter study or just one seventh of the highest prevalence rate that was found for age 17 Telephone surveys answered by proxies is a reliable and generally valuable source of information about health conditions of older probands.…”