Persistent ashen-gray maculae and freckles induced by long-term PUVA treatment.

Persistent ashen-gray maculae 5-7 mm in diameter and freckles developed after prolonged PUVA therapy of psoriasis. Histopathology of maculae showed extensive collections of melanophages in the upper dermis. The melanocytes were strongly stimulated at the site of the freckles. The number of melanosomes, mitochondria, endoplasmic reticulum and dendrites were increased. Pathological features such as large amounts of lipid droplets and lysosome-melanosome complexes were also found within the melanocytes.