Arsenic poisoning (AP) was once common. Arsenic's easy availability and organoleptic characteristics (tasteless and odorless) made it the most commonly employed element in criminal poisonings. As well, arsenic was frequently used in medicine to treat many diseases, such as psoriasis, syphilis, verruca plana, lichen planus, and epilepsy. Although its use is presently much more restricted, arsenic still remains a problem, and many cases of poisoning, whether accidental, industrial, or intentional are reported yearly. However, the clinical manifestations may appear unrecognized for clinicians who are not familiar with AP. Dermatologic manifestations are prominent in most cases of AP, and its knowledge may provide us the key to the diagnosis of AP. Mees' lines are true transverse bands of leukonychia seen during AP. However, they are seldom demonstrated in these patients.
In the last 8 years, we have seen four cases of AP, three of them with prominent Mees' lines, which constituted