Abstract
INTRODUCTION: Yellow urticaria (YU) is a rare variant of urticaria characterized by a transient yellow rash. It usually occurs at patients with hyperbilirubinemia. In clinic, the vasodilation and extravasation associated with urticaria facilitate the precipitation of bilirubin within the elastin fibers of the cutaneous tissue, which consequently leads to the emergence of atypical yellow papules and plaques. The occurrence of hyperbilirubinemia in cases of yellow urticaria is commonly attributed to underlying liver diseases, including infectious hepatitis, metastatic disease of the liver, liver cirrhosis due to various causes. Here, we report a case of YU secondary to platelet transfusion. PURPOSE: Red and purple rashes are common, whereas yellow wheals are rarely reported. Therefore, we are supposed to keep an eye on the diagnosis of YU. PATIENTS AND METHODS: We present a case of YU secondary to platelet transfusion that responds rapidly to anti-hypersensitive and antihistamine treatment. RESULTS: Based on the skin lesion and histopathology result, we considered that the patient developed YU. The patient with YU responds rapidly to anti-hypersensitive and antihistamine treatments, with no adverse effects or recurrence. The prognosis of YU is with favorable outcome. It seldom turns into chronic urticaria and occurs repeatedly. CONCLUSION: The exact pathogenesis of yellow urticaria remains uncertain. It has been proposed that the yellow coloration of the disease may result from the increased capillary permeability that cytokines and mediators, especially histamine, induce. Yellow hives are attributed to underlying hyperbilirubinemia with skin deposits and suggest underlying causes, particularly liver diseases. Conventional anti-hypersensitive and antihistamine treatments are effective in treating YU. Prophylactic and systematical use of antihistamine agents may prevent relapse.