Acute psychosis ??? [Ref: Kaplan and Saddock synopsis of Psychiatry 10/e p 516-5171We are unable to reach a conclusive diagnosis with the information provided in the question.Acute onset, presence of fever, no history of psychiatric illness suggests delirium.But, the diagnosis of delirium cannot be made definitively in the absence of disorientation.In the question there is no definite comment on orientation of the patient.May be, that suggests, the patient is not disoriented.Acute onset, presence of perceptual disturbances (hallucination and other symptoms point towards acute psychosis.But acute psychosis seems unlikely because:-- Absence of cognitive dysfunction or thought disorders.- Absence of H/o psychiatric illness or substance abuse disorders.Psychotic disorders cannot be diagnosed only in the presence of perceptual disturbances. Some disorder in cognitive dysfunction or thought disorders is also required.May be this is a case of acute transient psychosis- These disorders do not give the classical manifestations of psychotic disorders.- They are characterized by the predominance of perceptual disturbances, and they do not fulfil the criteria of psychotic disorders.Acute and Transient Psychotic disordersA large number of psychiatrists especially from the developing countries like India, repoed that many patients developed an acute psychotic disorder that neither followed the course of schizophrenia nor resembled mood disorders in the clinical picture and usually had a better prognosis than schizophrenia.Acute and transient psychosis as a descriptive entity was recognized only with the advent of 1CD-10 in 1992. Where it is included under psychotic disorder.- The key features that characterize the disorder are an -- acute within (2 weeks) onset in all the cases presence of typical syndrome which are described as rapidly changing variables, polymorphic states and typical schizophrenic symptoms evidence ,for associated acute stress in a substantial number of cases and complete recovery in most cases within 2-3 months.A pa from these criteria ICD-10 also provides diagnostic guide- lines which include- Not meeting the criteria for manic or depressive episodes although the affective symptoms may be prominent - Absence of organic causation although perplexity confusion and inattention may he present. - Absence of obvious intoxication by drugs or alcohol.It is evident that ICD 10 intends to "clearly differentiate" the concept of acute transient psychosis .from those of affective psychosis, organic psychosis and drug induced psychosis.This is the point which is creating doubt in our minds.The ICD wants to clearly differentiate it from organic psychosis.- The boy presents with "fever" therefore the organic cause for the psychosis cannot be ruled out. - May be the psychosis is due to fever (some C.N.S. infection)- If fever had not been mentioned the diagnosis would have been clear. But the presence of fever prevents us from diagnosing this as acute transient psychosis.- The correct option would have been "organic psychosis" or "psychosis due to general medical condition". - Acute psychosis cannot be diagnosed without addressing the organic basis of the disease.Four subtypes of acute transient psychosis are described in ICD 10 -Acute polymorphic psychotic disorder without symptoms of schizo- phrenia - Acute polymorphic psychotic disorders with symptoms (?f schizo- phrenia - Acute schizophrenia like psychotic disorder- Acute predominantly delusional psychotic disorderOverall, duration of total episode should not exceed 3 months and that .for schizophrenic symptoms should not exceed 1 month. There is provision for change of diagnosis to schizophrenia.