Exposure to cobalt may lead to allergic contact dermatitis in children: Study

USA: A new study findings report that allergic contact dermatitis (ACD) reactions are common among children exposed to cobalt, with the most common site being the trunk, face, and ears. The article was published in Contact Dermatitis.

An allergic contact dermatitis is a form of dermatitis/eczema caused by an allergic reaction to a material, called an allergen, which comes in contact with the skin. Nickel, cobalt, and chromates are the most frequent allergens. Allergic contact dermatitis is also called contact allergy. Cobalt is known as a strong skin sensitizer. Cobalt allergy affects nearly 2% of the general population and can develop at any age, including in children. A patch test is a diagnostic method used identification of the etiologic agent of ACD.

Previous research has indicated that ACD to cobalt is more common in children and adolescents than in adults. , ACD is often underdiagnosed due to a lack of patch testing and misdiagnosis. To date, detailed information on sites and sources of cobalt ACD is limited.

Jonathan I. Silverberg, Northwestern University Feinberg School of Medicine, USA, and his team conducted a retrospective analysis study to assess trends in positive and clinically relevant patch test reactions to cobalt in children and associated patient characteristics, common sources, and body sites affected.

Researchers analyzed 1,919 children (<18 years) patch tested for cobalt by the North American Contact Dermatitis Group. They used cobalt in the forms of cobalt chloride 1% in petrolatum (pet.) and cobalt chloride hexahydrate 1.0% pet. It was left on site for 48 hours, and readings were taken at both 48 hours and 72-168 hours following placement. Researchers graded reactions on positive and negative scales which ranged from non-vesicular, indurated erythema and macular erythema or irritant. Allergen sources were classified in 228 options and 11 categories.

Key findings of the study,

• 228 (11.9%) and 127 (6.6%) had a positive/allergic or currently relevant patch test reaction to cobalt, respectively.

• The most common primary body sites affected were scattered generalized (30.0%), face, not otherwise specified (NOS, 10.6%), and trunk (10.1%).

• Patients with allergic and currently relevant allergic patch test reactions were more likely to have a primary site of the trunk and ears.

• Affected body site(s) varied by cobalt source among patients with currently relevant reactions, especially for less common sources

• The most commonly identified sources of cobalt included jewelry, belts, and clothing.

The authors conclude that in children positive patch test reactions to cobalt were very common. Most common body sites were scattered and generalized, including the trunk, face, and ears as the primary site. Also, the cobalt sources, varied by variation in the body site.

Reference:

Jonathan I. Silverberg,Nisha Patel,Erin M. Warshaw,Howard I. Maibach,Donald V. Belsito,Joel G. DeKoven,Kathryn A. Zug,James S. Taylor,Denis Sasseville,Vincent A. DeLeo et al.  First published: 08 July 2022 https://doi.org/10.1111/cod.14185