Contact hypersensitivity to corticosteroids in routine patch test patients. A multi-centre study of the Swiss Contact Dermatitis Research Group

BACKGROUND: Contact hypersensitivity to corticosteroids is increasingly reported and has been identified as a problem of considerable clinical relevance. The prevalence of positive patch tests to corticosteroids ranges from 0.2 up to 5%. OBJECTIVE: The prevalence of positive patch tests to corticosteroids in Switzerland was determined in a multi-centre study of patients undergoing routine patch tests. METHODS: As representatives of corticosteroid groups, the following substances were used for screening: tixocortol pivalate and hydrocortisone for group A (hydrocortisone type), hydrocortisone butyrate for group D (hydrocortisone butyrate type) and budesonide for both groups B (triamcinolone type) and D. Patients positive for at least one corticosteroid were retested with the screening series and 12 corticosteroids commonly used in Switzerland. RESULTS: Among 3,016 consecutive patients, 65 individuals (2.2%) with a total of 106 positive reactions were found. Retesting showed a concordance of 70-98%, depending on the corticosteroid and the score of the positive reaction. In the subsequently tested corticosteroid series including 12 substances, 19 out of 56 screening-positive patients had a positive result to one or several corticosteroids. There were only few evident cross-reactive patterns in between the corticosteroids tested. CONCLUSIONS: Corticosteroids should be included in routine patch testing, because contact sensitization to a corticosteroid is of considerable practical importance. We confirm that as markers of corticosteroid sensitization tixocortol pivalate, budesonide and hydrocortisone butyrate may be suited, because there is no single corticosteroid which is a marker for all four corticosteroid groups. Patch test reactions of 2+ or higher have a better reproducibility than 1+ reactions

Dermatite alérgica de contato a medicamentos de uso tópico: uma análise descritiva Allergic contact dermatitis to topical drugs: a descriptive analysis

FUNDAMENTOS: A dermatite de contato é uma dermatose comum e suas múltiplas causas dificultam seutratamento. OBJETIVO: O objetivo do estudo foi avaliar a frequência da sensibilização aos medicamentos de uso tópico, em serviço universitário; estudar as características da população afetada e identificar os principais sensibilizantes relacionados aos medicamentos tópicos. MÉTODOS: Realizou-se um estudo retrospectivo dos pacientes com hipótese diagnóstica de dermatite alérgica de contato e que foram submetidos a testes epicutâneos. Avaliaram-se os que tiveram diagnóstico final de dermatite alérgica de contato a medicamentos tópicos. RESULTADOS: Em um grupo de 329 pacientes submetidos a testes de contato, 42 (13%) tiveram testes de contato positivos e relevantes para medicamentos tópicos, pelo princípio ativo e/ou por outros componentes. Entre os testes positivos, 36 (85,7%) corresponderam aos princípios ativos e 28 (66,7%), a outros componentes das fórmulas, com alguns pacientes apresentando mais de um teste positivo. Entre os princípios ativos, a neomicina foi o mais frequente. CONCLUSÕES: Entre os pacientes estudados, a sensibilização aos medicamentos tópicos ocorreu em 13% dos casos, com discreta preferência pelo sexo feminino e maior número de casos entre pacientes brancos. Houve elevada frequência de dermatite alérgica de contato pela neomicina, agente de uso comum como automedicação e também como prescrição médica.<br>BACKGROUND: Allergic Contact Dermatitis is a common type of dermatitis, but its multiple etiologies hinder its management. OBJECTIVE: the objective of this study was to evaluate the frequency of sensitization to topical drugs in a university center, to study the main characteristics of the affected population, and to identify the allergens related with the dermatitis. METHODS: a retrospective and descriptive study with patients submitted to patch tests. The study was conducted with subjects whose patch test to topical drugs was positive. RESULTS: 329 patients were submitted to patch tests and 42 (13%) had positive and relevant patch tests to topical drugs. Among these patients, 36 (85.7%) had positive patch tests to the principal component and 28 (66.7%) to the other components. Some patients had more than one sensitization. Neomycin was the most important allergen. CONCLUSIONS: Among the studied patients, sensitization to topical agents happened in 13% of the cases, with slight preference for females and Caucasians. There was elevated sensitization to neomycin, a popular agent among patients and medical doctors

Enzyme mediated site-specific surface modification

Stable tethering of bioactive peptides like RGD to surfaces can be achieved via chemical bonding, biotin streptavidin interaction, or photocross-linking. More challenging is the immobilization of proteins, since methods applied to immobilize peptides are either not specific or versatile enough or might even compromise the protein's bioactivity. To overcome this limitation, we have employed a scheme that by enzymatic (transglutaminase) reaction allows the site-directed and site-specific coupling of growth factors and other molecules to nonfouling poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) coated surfaces under physiological conditions. By our modular and flexible design principle, we are able to functionalize these surfaces directly with peptides and growth factors or precisely position poly(ethylene glycol) (PEG)-like hydrogels for the presentation of growth factors as exemplified with vascular endothelial growth factor (VEGF)