Portugal: A recent case study published in Contact Dermatitis has described a rare case of a woman in Portugal who developed a contact allergy to gold from a coffee cup.

"It is rare, but some individuals develop sensitivity to gold on tableware that manifests as a contact allergy," Cláudia Brazão and a team from Portugal wrote in their study. "Clinicians should remain vigilant for allergic contact dermatitis to gold from unusual sources and should be aware that positive results to gold on patch testing often appear late."

The case in question is of a 27-year-old woman with a 1-year history of burning, pruritus and fullness of the upper lip. The symptoms initiated when she started teleworking from home during the COVID-19 pandemic.
The patient did not report the use of any orthodontic braces or prostheses, fragrances, cosmetic products or other possible precipitants. Physical examination confirmed a mildly edematous upper lip. Patch testing was conducted with three series: the Dental Screening series, the Portuguese Group for Study of Contact Dermatitis baseline series, and the Bakery series.
The researchers did not observe any positive reactions on day two or day 4, but on day 7, the patient reported an itchy red papule at a patch test site. After one month, the patch tests were repeated, with late readings. On the 7th day, positive reactions were seen to gold sodium thiosulphate 2% in petrolatum (+++) and cobalt chloride 1% in petrolatum (+). They persisted until day 28.
On questioning, the patient reported twice-daily use of a coffee cup with a gold border and blue pattern since she started working from home a year earlier. The manufacturer confirmed that the cup had gold paint as well as cobalt.
The patient stopped using the coffee cup and experienced complete resolution of symptoms without recurrence at six months. A diagnosis of allergic contact dermatitis to gold was made.
Reference:
Brazão C, Fernandes S, Correia T, Filipe P. Contact allergy to gold from a coffee cup: An unusual source of sensitization. Contact Dermatitis. Published ahead of print May 19, 2023. doi: 10.1111/cod.14337.