A historic case of relapsing-remitting Alzheimer's disease in an adolescent attributed to scarlet fever.

We draw attention to a historic case of a boy who suffered from scarlet fever (typically caused by the bacterium Streptococcus pyogenes) at age 7 years and went on to develop the symptoms of Alzheimer's disease (AD). His physicians believed that the subsequent dementia was related to the infection. After death at 24 years of age, postmortem brain examination revealed abundant AD-type senile plaques and fibrils, formally confirming AD. Other potential causes of early-onset dementia are discussed, but these are distinct from patient E.H. This case is pertinent regarding the current debate about the potential role of infection in AD.