Abstract
A 61-year-old female patient presented to our department in mid-August with severely itchy and painful blisters and erythema on both hands, erosions on her lower lip, and erythematous papules on both cheeks. She was treated with the diagnosis of herpes virus infection at another dermatology clinic, otherwise no improvement was obtained. She visited our department four days after her initial visit.
Multiple erythema multiforme-like eruptions with partial confluence were preset on the face and forearms. The possibility of quena contact dermatitis syndrome or photocontact dermatitis was suspected, since the patient had started attending quena lessons 13 days before the onset of symptoms and the symptoms were more severe at the quena contact area. The skin rash improved with tapering treatment with oral prednisolone 20 mg/day as starting dose. The shaved body of the quena used and the jacaranda log that the patient declared as material for the quena were extracted with purified water or ethanol at 10%(w/v) for 24 hours each to make a patch test stock solution. The patch test showed that undiluted solutions of quena in purified water(++), 10x and 100x dilutions(+), undiluted solutions of quena in ethanol and 10x dilution (++), 100x dilution(+), undiluted solutions of jacaranda in ethanol(+?), and 1000x dilution(+?). Photo patch test showed the same results. Therefore, a diagnosis of contact dermatitis syndrome caused by quena was made. Analysis of the components of the quena used by the patient revealed that the material of the quena was not jacaranda, but the genus Machaerium which contains dalbergion-type substances. Although only one case of contact dermatitis due to quena has been reported in Japan, it is well known that quena is prone to contact dermatitis among quena enthusiasts. Therefore it is important to recognize that quena is a material with a high risk of contact dermatitis.
