PANDAS can present with chorea but more typically there are tics, stereotypies with a psychological component (e.g., OCD). Differential diagnosis
Other disorders that may be accompanied by chorea include benign hereditary chorea, bilateral striatal necrosis, abetalipoproteinemia, ataxia–telangiectasia, biotin-thiamine-responsive basal ganglia disease, Fahr disease, familial dyskinesia–facial myokymia (Bird–Raskind syndrome) due to an ADCY5 gene mutation, glutaric aciduria, Lesch–Nyhan syndrome, mitochondrial disorders, Huntingtons disease, Wilson disease, hyperthyroidism, lupus erythematosus, pregnancy (chorea gravidarum), drug intoxication and side effects of certain anticonvulsants (e.g. phenytoin) or psychotropic agents. Although some of these can similarly present in an acute way, there will typically be other neurological signs (such as ataxia or cognitive impairment), or other disease manifestations, or positive family history, which will help distinguish between them. Pathology
One of the important manifestations of acute rheumatic fever, Sydenhams chorea is similarly caused by an autoimmune response following infection by group A β-hemolytic streptococci.Two cross reactive streptococcal antigens have been identified, the M protein and N-acetyl-beta-D-glucosamine, whereby infection leads to autoantibodies being produced against host tissues (molecular mimicry) causing a variety of streptococcal related diseases including Sydenhams chorea but also rheumatic heart disease and nephritic syndrome. Autoantibodies against basal ganglia proteins have been found in Sydenhams chorea but these are non-specific. Dopamine receptor autoantibodies have been reported to correlate with clinical symptoms. Whether these antibodies represent an epi-phenomenon or are pathogenic, remains to be proven. Epidemiology
As with rheumatic fever, Sydenhams chorea is seen more often in less affluent communities, whether in the developing world or in aboriginal communities in the global North.
A myxoid cyst is a cutaneous condition often characterized by nail plate depression and grooves. See also
Scleroderma
List of cutaneous conditions
List of radiographic findings associated with cutaneous conditions


== References ==