Researchers reviewed nearly 7 years' worth of patch testing data to analyze trends in hand eczema in Latin America.
Main sensitizers leading to hand eczema (HE) and dermatitis may include Kathon CG, nickel sulfate, and thiuram mix.
In a recent study,1 researchers sought to determine common causes and triggers of several eczematous diseases including HE, irritant contact dermatitis (ICE), allergic contact dermatitis (ACD), and atopic dermatitis (AD). They cited Latin America’s lack of epidemiological studies of a similar nature, or of answering their question of disease etiology.
“A study is necessary to characterize the population profile, which could contribute to the understanding of the issue in the studied country and provide relevant information so that, based on this information, effective prevention strategies can be outlined for the problem,” study authors wrote.
A group of researchers conducted the retrospective descriptive study at a dermatology clinic in São Paulo, Brazil. They included all patients who presented to the clinic with HE (or suspected HE) who underwent patch testing during their time there and did not meet exclusion criteria (n=173).
Patients were excluded from the study (n=11) if they were pregnant, did not consent to their data use, did not attend their patch test reading, or if they had incomplete data in their medical records or contraindications upon the time of their patch testing. Contraindications included recent sun exposure, use of systemic corticosteroids, and acute eczema.
Patch test results were read at 48 and 96 hours post application of the allergenic substances to the patient’s back. Researchers assessed the outcomes using morphological criteria from the International Contact Dermatitis Research Group. They analyzed the outcomes for common skin reactions such as redness, papules, and vesicles.
Researchers analyzed several factors, including:
Based on the above criteria, study participants were then given relevant clinical diagnoses of ICD (n=107), ACD (n=98), AD (n=40), and other (n=9). This accounts for participants with overlapping or numerous eczematous conditions.
Participants were then analyzed based on reactions to nearly 40 substances, including 5 of the substances being the most frequently reaction-causing in patients with ACD: Kathon CG (n=42%), nickel sulfate (n=33%), thiuram mix (n=18%), potassium bichromate (n=17%), and carba mix (n=17%).
According to the study, previously known risk factors for developing HE include sex (females), age (individuals predominantly younger than age 20), frequency of handwashing or wet work, and patient history of AD. Researchers found that their data aligned with previously understood factors involved with eczematous diseases.
“The main sensitizers found in the present study are in agreement with the literature, with nickel sulfate and preservatives occupying the top positions,” study authors wrote.
Historically, Latin Americans face health care disparities that cause AD to be significantly more prevalent in individuals living in the region.2 Ethnic, political, racial, regional, and socioeconomic factors may play a role.
“In Latin America, the prevalence of atopic dermatitis (AD) is reportedly as much as 25% in children and 1%-3% in adults, according to numerous papers and studies on the disease,” wrote Keith Loria for Dermatology Times. “Historically, AD goes into remission in adolescence and adult life, with approximately 10%-30% of patients continuing to experience symptoms of AD in adulthood.”