Mode of enquiry -what is the duration of fever less than 1 week is short fevershort viral fever,tonsillitis prolong

1. Mode of enquiry -what is the duration of fever? less than 1 week is short fever(short viral fever,tonsillitis) prolonged fever is fever persisting for more than 2weeks (enteric fever,malaria) Pattern of fever

2. Mean oral temperature 36.8 plus or minus 0.4 98.2 0.7 With low levels at 6 am,higher levels at 4-6pm Maximum oral temperature is 37.2 at 6am 37.7 at 4pm The normal daily variation is typically 0.5c Rectal temperature are 0.4 higher than oral readings

3. Lower-oesophageal temp closely reflect core temperature Tympanic membrane thermometers measure radiant heat from the tympanic membrane and nearby earcanal

4. Fever is elevation of body temperature above the normal circadian variation and occurs in conjunction with an increase in hypothalamic set point(from 37 to 39c) 

5. Body temperature is controlled by balancing heat production against heat loss Heat production Different factors that determine the rate of heat production-called metabolic rate of body 1)basal rate of metabolism of all cells of body 2)extra rate of metabolism caused by muscle activity,muscle extractions caused by shivering

6. 3) caused by effect of thyroxine(other hormones such as GH,Testosterone) 4)caused by effect of epinephrine,norepineprine,sympathetic stimulation 5)extra metabolism caused by increased chemical activity in cells Extra metabolism needed for digestion,absorption and storage of food

7. Heat loss-radiation,conduction,convection,evaparation Blood flow to the skin from the bodycore provides heattransfer Regulation of body temperature-role of hypothalamus

8. Receptors in other parts of body play additional roles in temperature regulation -temperature receptors in skin -specific deep tissues of body Role of posterior hypothalamus

9. Temperature decreasing mechanism when body is too hot Vasodilatation of blood vessels Sweating Decrease in heat production Temperature increasing mechanisms Skin vasoconstriction Piloerection Increase in thermogenesis

10. Increase in thermogenesis -by promoting shivering -sympathetic excitation of heat production -Thyroxine secretion

11. Pathogenesis of fever Exogenous pyrogens endogenous pyrogens or pyrogenic cytokines

12. Continued fever- Remittant fever Intermittant fever-quatidian tertian quartan Pel ebstein fever Fever of cyclic neutropenia Step ladder fever

13. What are the accompanying symptoms that help in diagnosis? -fever with rigor and chills-malaria,uti,abscess -dysuria and vomiting-uti severe myalgia of back and thigh muscles �leptospirosis Headache ,siezure and vomiting-cns infection Nasal discharge and facial pain-sinusitis

14. Throat pain and dysphagia-tonsillitis Cough and purulent sputum-respiratory infection Blood and nucus in stools-dysentery Jaundice and fever-suggests hepatitis;malaria,leptospirosis,dengue fever Acute cva with hyperpyrexia-pontine haemorrhage

15. Is there a history of consumption of raw or poorly cooked meat,raw fish-food poisoning Did he have insect bite/tick bite Contact with animals Mosquiito bite-malaria ,dengue,filariasis Flea bite-plague,tularemia Sand fly bite-lieshmaniasis,arbovirus

16. Tick bite-typhus,KFD,lymes desease Animal contact-Qfever,brucellosis,rabies,plague,anthrax,viral haemarrhagic fever,histoplasmosis Does he have loss of apetite,wieght loss,aches and pain?-suggests malignancy,and chronic illness Is there history of multisystem involvement-suggests collagen vascular desease

17. Recent exposure to ill individuals Exposure to sexually transmitted disease If he has rash ask for siteof onset of rash,its direction,and rate of spread Does he have any valvular heart desease Ask for respiratory,genitourinary,abdominal and joint symptoms Has he travelled recently-suggests malaria,typhoid,hepatitis,amoebiasis

18. Past history Does he have DM? Is he on drugs like cephalosporins,sulfa,anti TB,phenytoin,methyldopa,quinidine which can cause fever History of intake of steroids or other immunosuppresive drugs Did he suffer from TB?does he have contact with TB or other infections?

19. Has he undergone any heart surgery and is on prosthetic valves? What is the immune status of the patient?does he have HIV FAMILY HISTORY TB,other infectious deseases,collagen vascular desease

20. PERSONAL HISTORY Is there history of extra marital contact? Is he addicted to any recreational drugs? Does he consume alcohol-suspect fever due to alcoholic hepatitis,cirrhosis with SBP,and hepatocellular carcinoma Occcupational history �toxic fumes,infectious agents

21. FEVER OF UNKNOWN ORIGIN Defined by ptesdorf and beeson in 1961 1)fever more than 101 on several occasions 2)duration more than 3 weeks 3)failure to reach a diagnosis after one week of inpatient investigation

22. UPDATE OF INITIAL DEFINITION In 1991 durack and Street Uncertain diagnosis after atleast 3 outpatient visits or atleast 3 days in hospital 4 groups Classic FUO,nosocomial FUO,neutropenic FUO,HIV associated FUO

23. MODERN DEFINITION OF CLASSIC FEVER OF UNKNOWN ORIGIN Illness of more than 3 weeks duration Tenperature of atleast 38.3 or lower temperature with laboratory signs of inflammation,on atleast 3 occasions No diagnostic or reasonable diagnostic hypothesis after initial diagnostic investigation Exclusion of nosocomial fevers and severe immunocompromise

24. Common causes of classic fever INFECTIONS- TB,endocarditis, Abdominal and hepatobiliary infections Genitourinary infections Pleuropulmonary infections Bone and joint infections Salmonellosis Cytomegalovirus,EBV, HIV

25. NEOPLASMS Haematological-luekaemia,NHL,hodgkins lymphoma solid-adenocarcinoma(colon,kidney) NON INFECTIOUS INFLAMMATORY DESEASE Connective tissue disease-RA,SLE Vasculitis syndromes-giant cell arteritis,Polyarteritis nodosa Granulomatous disrders-sacoidosis,IBD

26. MISCELLANEOUS Drug fever Factitious fever Habitual hyperthermia

27. Nosocomial FUO -Fever more than 101F occuring several times in an inpatient in whom infection was not present or not incubating infection on admission -minimum duration for diagnosis is 3 days of investigation including atleast 2days of culture -causes are ,occult nosocomial infection infected catheter lines tranfusion related viral infection drug fever

28. NEUTROPENIC PUO Fever more than 101F in a patient with <500 neutrophils Duration for diagnosis-3 days of investigation Candida ,aspergillus infection,perianal infections,herpes simplex virus

29. HIV ASSSOCIATED PUO Fever more than 101F for more than 4 weeks for out patients or more than 3 days for inpatients in HIV confirmed case Mycobacteriun infection,toxoplasmosis,cmv infection,pneumocystis infection,drug fever,

30. HYPERTHERMIA Is elevation of body temperature without elevation of hypothalamic set point and is due to insufficient heat dissipation Heat stroke Malignant hyperthermia Neuroleptic malignant syndrome Serotonin syndrome

31. Drug induced hyperthermia -amphetamines,salicylates,lithium,anticholinergics,sympathomimetics,LSD Endocrinopathy Central nervous system damage