Chronic and Stubborn Leuco-melanoderma in a Child: A Case Study

Aims: Pityriasis lichenoides chronic is a rare inflammatory dermatosis, unusually hypochromic in dark phototypes. The evolution of the disease is usually benign, but a malignant transformation in mycosis fungoides is reported. You have to know how to think about it when faced with a generalized hypochromic macular eruption in children.

Case Report: We report a case of a 13-years-old child, photo type 4.He presented for 8 months hypochromic macular lesions, located initially at the face. The evolution was marked by the extension at the trunk and the limbs. He was treated for pityriasis versicolor but without improvement. A skin biopsy was then performed, in favor of Pityriasis Lichenoides Chronica (PLC) with a lymphoid infiltrate made up mainly of CD4 T lymphocytes. The child was put on cyclin associated with heliotherapy with a moderate improvement after 3 months of treatment. The patient was followed for 2 years during which he did not present any malignant transformation.

Discussion: Pityriasis Lichenoides is less frequent in the pediatric population.Its etiopathogenesis is still incompletely elucidated. The basic lesion is an erythematous-squamous papule in the trunk. Hypochromic macules can also be observed, either at the cicatricial stage of the disease, or they occur immediately, especially in subjects with dark skin. The histology of PLC reveals perivascular lymphocytic infiltrate in the superficial dermis..The adopted therapeutic is based on heliotherapy or an antibiotic from the macrolide or cyclin family. Evolution towards Mycosis Fungoides has been rarely described.

Conclusion: PLC is exceptionally hypopigmented from the outset. We report a case of chronic leucomelanodermic pityriasis lichenoides in a child posing a problem of differential diagnosis.