Urticaria and infections

Urticaria is a group of diseases that share a distinct skin reaction pattern. Triggering of urticaria by infections has been discussed for many years but the exact role and pathogenesis of mast cell activation by infectious processes is unclear. In spontaneous acute urticaria there is no doubt for a causal relationship to infections and all chronic urticaria must have started as acute. Whereas in physical or distinct urticaria subtypes the evidence for infections is sparse, remission of annoying spontaneous chronic urticaria has been reported after successful treatment of persistent infections. Current summarizing available studies that evaluated the course of the chronic urticaria after proven Helicobacter eradication demonstrate a statistically significant benefit compared to untreated patients or Helicobacter-negative controls without urticaria (p < 0.001). Since infections can be easily treated some diagnostic procedures should be included in the routine work-up, especially the search for Helicobacter pylori. This review will update the reader regarding the role of infections in different urticaria subtypes

Alopecia areata and affected skin CRH receptor upregulation induced by acute emotional stress

Background. Recent evidence indicates that acute stress can precipitate a number of dermatological conditions, including alopecia areata. This effect may be mediated by corticotropin-releasing hormone (CRH) released locally in the skin from dorsal root ganglia or immune cells. CRH typically acts through activation of specific receptors that are either type 1 or types 2 alpha and 2 beta. CRH, or related peptides such as urocortin, could have proinflammatory effects directly or through activation of mast cells leading to destruction of the hair root. Objectives: To investigate the expression of CRH receptors on the affected skin of patients who developed alopecia areata following acute emotional stress. Methods: Scalp skin biopsies were obtained from 1 normal volunteer and 3 patients after ring infiltration of the relevant site with lidocaine. The biopsies were frozen and were later processed for in situ hybridization for CRH receptors type 1 or types 2 alpha and 2 beta. Sections showing positive results were photographed. Results: The skin from the normal volunteer showed weak background expression of all three receptor types. However, skin from the affected sites of all 3 patients studied showed intense expression only on the type 2 beta receptor around the hair follicles. Conclusion: Acute emotional stress may precipitate alopecia areata by activation of overexpressed type 2 beta CRH receptors around the hair follicles leading to intense local inflammation. Copyright (C) 2001 S. Karger AG, Basel

The Effect of Atopy in the Prevalence of Contact Sensitization: The Experience of a Greek Referral Center

Contact dermatitis is a well-known skin condition, which is related to stimuli and environmental exposure to chemicals, affecting all ages as well as both genders. In the present work, we attempt to investigate the patterns of contact sensitization, with respect to the personal history of atopy (AT), in Greece in a large number of allergens, using patch testing. The retrospective analysis included clinical routine data of 1978 patients collected from 2014 to 2016 in the Laboratory of Patch Testing, National Referral Centre of Occupational Dermatoses. Sensitization, in all cases, was tested with 28 allergens of the European baseline series as adjusted to our local circumstances and clinical experience. A total population of 1978 patients was evaluated, with a male-to-female ratio of 0.45 (1359 females/619 males). From our patient cohort, 693 (35%) patients were evaluated with a history of atopy, while 1285 (65%) were nonatopic. The five most prevalent allergens in the total population without AT were nickel sulphate 5% (15.47%), fragrance mix (I) 8% (9.10%), balsam of Peru (6.47%), cobalt chloride 1% (4.70%), and thiomersal 0.1% (4.10%). Respectively, in the total population with AT, the five most prevalent allergens were nickel sulphate 5% (10.36%), fragrance mix (I) 8% (5.11%), balsam of Peru (3.29%), thiomersal 0.1% (3.03%), and cobalt chloride 1% (2.78%). Contact dermatitis surveillance is of great importance towards the clinical and systematic understanding of the disease. Further studies should be directed towards that end, in order to facilitate more effective health policies. © 2020 Anna Tagka et al

Contact allergens in patients with leg ulcers

Background Contact dermatitis can complicate the treatment of leg ulcers and is an acquired phenomenon resulting from the use of topical medications. Objective To show the incidence of contact dermatitis reactions to topical medications applied to leg ulcers and to evidence changing trends in such reactions through comparison of two case series about 20 years apart. Subjects and methods We studied two groups of patients with leg ulcers that were patch tested with contact allergens in 1973-1974 and in 1994-1995. Results One or more positive patch tests was present in 75% and 40% of the patients, respectively. A decrease in the incidence of positive reactions to neomycin, local anesthetics and parabens mix was seen in 1994-1995. The most important contact allergens in 1994-1995 were fragrance mix, colophony and the excipients wool alcohols and amerchol. Other relevant sensitizers were formaldehyde, neomycin and gentamycin. Conclusion The changing trends in contact allergens over the last 20 years may be explained by changes in the components of topical agents used for treatment. (C) 1998 Elsevier Science B.V. All rights reserve

Photoallergic contact dermatitis: The 15-year experience of a tertiary reference center in a sunny Mediterranean City

Photoallergic contact dermatitis (PACD) represents an important entity of photodermatoses while photopatch testing is the main diagnostic tool. The main goal of this study is to evaluate retrospectively the prevalence of photoallergic reactions and the offending agents in Athens during a 15-year period. The medical records of all patients with possible PACD between 1992 and 2006 were examined. All patients included in the analysis had undergone patch testing and photo-testing. Contact reactions were detected in 86 out of 207 participants (41.54%), while photocontact reactions were identified in 28/207 (13.52%) patients. The most common offending photoallergen was promethazine (25%), while chlorpromazine and oxybenzone were both detected in 12.5% of cases. PACD represents a unique proportion of photodermatoses in a sunny Mediterranean city such as Athens. Copyright © by Biolife, s.a.s