A lprostadil (prostaglandin E1, PGE1) is commonly used for palliative therapy to temporarily maintain the patency of the ductus arteriosus (DA) until corrective or palliative surgery can be performed in neonates with ductus-dependent congenital heart defects such as tricuspid atresia, pulmonary stenosis, pulmonary atresia, interruption of the aortic arch, tetralogy of Fallot, coarctation of the aorta, or TGA with or without other defects. Alprostadil is a synthetic prostaglandin E1 and possesses pharmacological effects, including vasodilation by direct effect on the vascular smooth muscle. DA is constituted by smooth muscle cells which are especially sensitive to alprostadil. 1-3 Adverse effects of alprostadil infusion include apnea, hypotension, hypokalemia, bradycardia, gastric outlet obstruction, feeding difficulties, fluid electrolyte imbalance, fever, jitteriness, leukocytosis, cutaneous flushing, and peripheral edema. 4-6 There is a lack of cutaneous effects data. Our research presents a neonate who developed migratory polycyclic erythema of urticaria during treatment with alprostadil. Case Report A full-term male neonate was diagnosed with complex heart disease. His diagnosis included Taussig-Bing anomaly, TGA, large subpulmonic VSD, large PDA, severe coarctation, and interrupted aortic arch. The patient was transferred to our institution, a super-tertiary care for probable management within 5 hours after birth. The 3.3 kg infant was delivered by cesarean section. Cyanosis was noted at birth. The hypoxemia and cyanosis did not improve after using an oxygen mask with bag (oxygen saturation 80%). Intubation with subsequent mechanical ventilation was initiated in this case. Ampicillin and cefotaxime were administered for possible early neonatal sepsis. An echocardiogram revealed dextro-Transposition of the great arteries (d-TGA), large subpulmonic VSD, left aortic arch, large PDA, hypoplastic aortic arch, severe coarctation, and interrupted aortic arch. Alprostadil was started within 3.5 hours after birth. Arterial switch operation (ASO) was planned. The patient's intravenous medications included dopamine, dobutamine, fentanyl, furosemide, calcium gluconate, sodium bicarbonate, potassium chloride, ampicillin, cefotaxime, and heparin.