The fast development of vaccines against the novel coronavirus disease is among the most critical steps taken to control this potentially fatal viral disease. Like other vaccines, the coronavirus disease 2019 (COVID-19) vaccines can also cause unwanted reactions. Erythema multiforme (EM) is among the oral mucocutaneous side effects of COVID-19 vaccines. This study aimed to comprehensively review the reported cases of EM since the global onset of COVID-19 vaccination. Data from 31 relevant studies regarding the type and dose of COVID-19 vaccines administered, time of initiation of symptoms, age, and gender of patients, site of involvement, patients’ medical history, and treatment options were extracted. In total, 90 patients were identified with EM as a side effect of COVID-19 vaccination across studies. EM had the highest frequency after receiving the first dose of mRNA vaccines in older individuals. The first symptoms of EM appeared in less than 3 days in 45% and after 3 days in 55% of patients. EM is not a common side effect of COVID-19 vaccination, and fear of its occurrence should not impede vaccination.

Pial arteriovenous fistulas (pAVF) are rare vascular lesions consisting of one or more arterial connections to a single venous channel without any intervening nidus of vessels or capillaries. Case 1: A 65-year-old woman with a complaint of headache and left hand paresthesia was referred to us. Magnetic resonance imaging showed a large saccular lesion with signal void in the posterior part of the right sylvian fissure and catheter angiography showed a giant venous aneurysm fed by one branch of the middle cerebral artery (MCA) and draining into the vein of Trolard. Case 2: A 12-year-old boy was transferred to our hospital with a history of sudden loss of consciousness and hemiplegia. Brain computed tomography revealed a massive hemorrhagic mass in the right hemisphere and cerebral angiography showed a pAVF with a large aneurysmal varix, which was fed by multiple branches of the right MCA and draining into the superior sagittal sinus. Both patients underwent craniotomy and after ligation of vascular connections, aneurysmal varices were removed completely. Surgical resection can be a safe method for treatment of pAVFs, particularly in those with large varices.
Aged ; Aneurysm ; Angiography ; Arteriovenous Fistula* ; Brain ; Capillaries ; Catheters ; Cerebral Angiography ; Child ; Craniotomy ; Female ; Hand ; Headache ; Hemiplegia ; Humans ; Ligation ; Magnetic Resonance Imaging ; Male ; Microsurgery ; Middle Cerebral Artery ; Paresthesia ; Superior Sagittal Sinus ; Unconsciousness ; Varicose Veins* ; Veins