Background: Pigmentatio maculosa eruptiva idiopathica is a rare pediatric disease characterized by asymptomatic, brownish macules involving the neck and trunk with no preceding inflammatory process or history of drug exposure.
Methods: A 9-year-old girl presented with brown-gray, nonconfluent, asymptomatic macules on the trunk, neck, and limbs, ranging from 5 to 30 mm in diameter. The macules appeared suddenly with no lesions preceding their occurrence. Histopathologic examination showed basal cell layer hyperpigmentation, and abundant melanophages with a mild perivascular lymphohistiocytic infiltrate in the papillary dermis.
Results: The lesions disappeared spontaneously 1.5 years later with no therapy. No relapse occurred.
Conclusion: Pigmentatio maculosa eruptiva idiopathica must be differentiated from other skin disorders with hyperpigmentation in pediatric practice in order to avoid unnecessary treatment, as spontaneous resolution is expected. Following a literature review, we underline the importance of spontaneous regression as an additional clinical feature for this disease.