We report the case of a girl of 2 years and a half, without a notion of consanguinity, admitted for erythema of both cheeks which appeared 40 days after birth. In view of the notion of photosensitivity and the appearance of poikiloderma found in the clinical examination, the diagnosis of Rothmund Thomson syndrome was retained. Rothmund Thomson syndrome is a rare genetic disorder with autosomal recessive inheritance. It is characterized by the early onset of poikiloderma associated with various cutaneous and extra-cutaneous abnormalities with an abnormally high incidence of cutaneous cancers. There is no treatment of the disease, the care is limited to its consequences