In children, Sneddon syndrome, also known as idiopathic livedo reticularis with cerebrovascular accidents, is a very rare (and likely underdiagnosed) syndrome that consists of ischemic strokes and generalized livedo racemosa. Less than a dozen cases are reported in children and there may be confusion between Sneddon syndrome, cutis marmorata telangiectatica congenita, and Moyamoya syndrome. Knowing which individuals with persistent livedo reticularis are most prone to cerebral vascular occlusion would be very important for affected individuals, but this is not yet possible.

The key cutaneous feature is a persistent livedo reticularis, often in a livedo racemosa pattern (a form of livedo reticularis consisting of a large branching pattern, usually on the trunk, limbs, and proximal extremities). Individuals with Sneddon syndrome, including children, may have antiphospholipid antibodies. The prevalence has been reported to be from 0% to 85%. Regardless of whether patients have antiphospholipid antibodies, individuals with Sneddon syndrome have occlusive arteriopathy and endothelial damage. Up to 35% will have antiendothelial cell antibodies.

Clinical features:

• Livedo racemosa – Often precedes the onset of focal neurologic symptoms.
• Headache and vertigo – Most frequent symptoms; may precede livedo racemosa by several years but are nonspecific.
• Ischemic strokes – Most symptoms are from middle cerebral artery infarcts and thalamic infarcts: hemiparesis, sensory alterations, and aphasia. Less commonly, there may be dysarthria, visual field deficits, or sudden spontaneous falls.
• Transient ischemic attacks
• Vascular dementia
• Secondary symptoms and other organ manifestations in children include growth and intellectual disability.
• Moyamoya disease – In childhood, presents with ischemic attacks or strokes with occluded intra- and extracerebral arteries. Skin manifestations are not common symptoms of the disease.