Dermatite alérgica de contato a medicamentos de uso tópico: uma análise descritiva

Abstract

INVESTIGAÇÃOResumo: FUNDAMENTOS: A dermatite de contato é uma dermatose comum e suas múltiplas causas dificultam seu tratamento. 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 fór-mulas, 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. Palavras-chave: Dermatite de contato; Dermatite de contato/etiologia; Eczema; Neomicina; Neomicina/efeitos adversos Abstract: 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.

Frequency and trends of contact allergy to and iatrogenic contact dermatitis caused by topical drugs over a 25-year period

“…A higher proportion of leg dermatitis, accompanied by a high proportion of older patients, has often been found to be linked to a high prevalence of contact sensitization to topical medicaments. Also, patients with stasis dermatitis are at high risk , which can be explained by local inflammation, an impaired skin barrier, and the use of occlusive bandages favouring skin penetration, together with the use of multiple topical medicaments and dressings. The last of these were not taken into account in this study, but were recently found to account for 19% of the reactions in chronic leg ulcer patients .…”

“…The main active pharmacological agents involved are local antibiotics, antiseptics, non‐steroidal anti‐inflammatory drugs (NSAIDs), local anaesthetics, and corticosteroids , whereas the most frequent reported actual causes of photo‐allergic contact dermatitis are NSAIDs and, previously, the anti‐histamines promethazine and derivatives , which are used less commonly today. The frequencies of sensitization to specific active principles and trends in frequencies over the years, in particular, have been poorly described ; hence, these aspects are addressed in this study.…”

Iatrogenic Contact Dermatitis in a Patient with Atopic Dermatitis

“…Contact dermatitis due to topical medications can be iatrogenic or caused by a patient's self-medication (8). Often associated with allergic CD, the causative agent may be the medication's active ingredient or one of its vehicles, including excipients, preservatives, antioxidants, emulsifiers, and fragrance components.…”

“…There are two primary forms of CD, irritant and allergic. Irritant CD due to topical substances is triggered by agents that cause direct tissue damage without prior sensitization, whereas allergic CD results from sensitization to a substance that induces a cell-mediated type IV hypersensitivity reaction (8). to developing CD due to topical drugs as a result of the modified skin barrier (in the same manner as in patients with AD), and they are frequently exposed to these medications.…”

Assessment of patch test results carried out during ten years in a city in southern Brazil

“…The etiologic agents can be either the active substance or the ingredients (preservatives, acidulants, emulsifiers), many also found in cosmetics. 13 …”