Postsclerotherapy Hyperpigmentation: A Histologic Evaluation

The study evaluated postsclerotherapy hyperpigmentation, which occurred in 10-30% of patients after sclerotherapy of vessels 0.1-5 mm in diameter. The hyperpigmentation was linked to factors such as solution strength, vessel fragility, injection pressure, and solution type. Histologic analysis indicated that the pigmentation was due to the extravasation of red blood cells and hemosiderin deposition, rather than melanocytic alteration. Treatments like hydroquinones, trichloroacetic acid, and phenolic peeling agents had variable success. While 80% of affected patients cleared spontaneously within 6-24 months, some experienced persistent pigmentation for up to 5 years.