Complications
The complications of scarlet fever include septic complications due to spread of streptococcus in blood and immune-mediated complications due to an aberrant immune response. Septic complications—today rare—include ear and sinus infection, streptococcal pneumonia, empyema thoracis, meningitis and full-blown sepsis, upon which the condition may be called malignant scarlet fever.
Immune complications include acute glomerulonephritis, rheumatic fever and erythema nodosum. The secondary scarlatinous disease, or secondary malignant syndrome of scarlet fever, includes renewed fever, renewed angina, septic ear, nose, and throat complications and kidney infection or rheumatic fever and is seen around the eighteenth day of untreated scarlet fever.
An association between scarlet fever and hepatitis has been recognized for several decades. The mechanism of causation is not known.
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