[Mercury erythema after accidental exposure to mercury vapor]

Mercury exanthem can be considered as a systemic contact dermatitis following exposure to mercury vapor in patients with a prior sensitization to mercurials. It is characterized by a symmetrically distributed erythematous eruption appearing predominantly in the major flexural areas, in the neck, the lower portion of the abdomen and the upper anteromedial part of the thighs. In some cases, small pustules develop over the erythematous surfaces. We report our observations of two patients with mercury exanthem after exposure to mercury vapor caused by a broken thermometer. One of these patients presented with an unusual bullous form of mercury exanthem. Although diagnosis of mercury exanthem can be essentially based on clinical features, confirmation of the patient's exposure to mercury should be obtained. Cutaneous patch tests often prove the sensitization to mercurials.