Reviewing the evidence on nodding syndrome, a mysterious tropical disorder.

Objectives: To review the literature on the prevalence, clinical manifestations, pathogenesis, treatment, and implications of nodding syndrome (NS).

Methods: This is a narrative review.

Results: NS is a mysterious tropical disorder that is emerging in South Sudan, southern Tanzania, and northern Uganda.

A 24-year-old Ethiopian farmer with burning feet.

Podoconiosis is a non-infectious tropical disease caused by exposure of bare feet to irritant alkalic clay soils. This causes an asymmetrical swelling of the feet and lower limbs due to lymphoedema. This swelling is called "elephantiasis" and may lead to severe disability of the patient.