Berloque dermatitis is due to contact with

Berloque dermatitis By 5-methoxypsoralen (bergapten) in bergamot oil contained in perfumes. Term arose from the method of applying perfume to the sides of the neck and upper chest in a pendant shape (berloque is French for pendant). Wavelengths of UV light above 320 nm and hot humid conditions our absorption. Deep-brown pigmentation follows the pattern formed by the trickle of the droplets of perfume over the skin from their points of application.