[An infant with macules and papules].

Polymorphic maculopapular cutaneous mastocytosis (PMCM) is caused by proliferation of mast cells in the skin. It is commonly seen in infants. Although mastocytosis usually only affects the skin, systemic mastocytosis should be ruled out in cases with extensive presentation. PMCM resolves spontaneously before puberty in most cases. A 6-month-old male presented with asymptomatic cutaneous erythematous patches all over the skin. Darier's sign was positive. A diagnosis of polymorphic maculopapular cutaneous mastocytosis was made. Because of the extensive skin lesions, the patient was referred to a paediatrician. Tryptase levels were elevated but blood tests did not suggest systemic involvement. The parents were given an EpiPen Jr because of increased risk of anaphylactic shock.