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cdd , also known as heller 's syndrome or disintegrative psychosis , is a rare condition ( 1.7 cases per 100,000 ) characterised by late onset ( > 3 years of age ) of developmental delays in language , social function and motor skills .
it is grouped with the pervasive developmental disorders ( pdds ) and is related to the better known and more common disorder of autism .
although recognised for many years , research on this condition is less advanced than that in autism .
the present case report describes a child who developed cdd at the age of 6 years after an episode of chicken pox .
master d , 8 years and 1 month old child , was admitted with chief complaints of hyperactivity , increased talkativeness and no social reciprocity since last 2 years .
history of present illness revealed an episode of fever with rash , diagnosed to be chicken pox for a period of 15 days about 2 years ago .
after 15 days of asymptomatic period , the patient developed fearfulness , decreased social interaction and decreased speech production for next 2 months .
after this , gradually patient developed new symptoms  continuous irrelevant speech , verbal stereotypy , markedly increased motor activity , no social and emotional reciprocity , no eye to eye contact , decreased performance in activities of self help .
the above mentioned symptoms developed within a period of 1 month and were stable after that .
electroencephalogram ( eeg ) showed occasional bursts of spike and sharp wave discharges , though clinically there was no evidence of seizure disorder . in the ward , child would remain hyperactive most of the time and would run here and there without any purpose .
when someone would try to talk to him , he would not make eye to eye contact and would continuously utter irrelevant things .
he would repeat some phrase multiple times without any meaning . to confirm the diagnosis , autism diagnostic interview
 revised ( adi - r ) was applied and a diagnosis of cdd was made on the basis of following items  onset of symptoms after the age of 3 years , normal development of language before illness , loss of language and loss of purposive hand movement , loss of motor skills and loss of self help skills .
vineland adaptive behaviour scales ( vabs ) , 2 edition ( vineland ii ) was applied to actuate the age of the skills before and after the illness and it also showed significant loss of skills in each sub - domains of communication , daily living and social skills .
various viral infections have been known as the first event leading to the development of cdd . to the author 's knowledge cdd
this case represents a rare and interesting complication of chicken pox in a boy of age 6 years with normal development , developing cdd within short span of time .
the typical age of onset of cdd is 3 - 4 years . though case reports have mentioned age of onset between 1 and 9 years . in our patient , age of onset
. such late age of onset has been reported in few cases . in childhood disintegrative disorder , there significant loss of previously acquired skills in at least two of the following areas  expressive or receptive language , social skills , bowel or bladder control , play behaviour or motor skills . in our patient also , there was marked loss of most of the above mentioned skills .
the core features of cdd are loss of communication skills , marked regression of reciprocal interactions and the onset of stereotyped movements and compulsive behavior . in our patient , these features were present . in most cases the intellectual deficit becomes static or shows some amount of recovery . in our patient
the patient showed significant regression of milestones within short span of time and non - progressive course after that .
the present case report aims to alert the clinicians about the possibility of developing cdd , when seeing a case of chicken pox , especially when there is presence of regression of developmental milestones .
childhood disintegrative disorder ( cdd ) is characterized by late onset ( > 3 years of age ) of developmental delays in language , social function and motor skills . 
 commonly there is no antecedent physical disorder leading to childhood disintegrative disorder . 
 the present case report describes a child who developed childhood disintegrative disorder at the age of 6 years after an episode of chicken pox .