Approach to a Case of Fever and Heat Disorders PDF

Lecture 1 Approach to a case of fever and heat disorders Approach to a case of fever and heat disorders 1 Introduction Hyperthermia  is a state of elevated core temperature that rises rapid...

Lecture 1 Approach to a case of fever and heat disorders Approach to a case of fever and heat disorders 1 Introduction Hyperthermia  is a state of elevated core temperature that rises rapidly above 40°C, secondary to failure of thermoregulation, that occurs when a body produces or absorbs more heat than it dissipates. Hyperpyrexia  is the term for an extraordinarily high fever (>41.5°C), which can be observed in patients with severe infections but most commonly occurs in (CNS) hemorrhages. Hypothermia  may signal the presence of an overwhelming infection and should therefore be evaluated just as thoroughly as hyperthermia The pattern of temperature changes may occasionally hint at the diagnosis:  Continuous/Sustained Fever:  Temperature remains above normal throughout the day and does not fluctuate more than 1 °C in 24 hours, e.g. lobar pneumonia, typhoid fever, urinary tract infection, brucellosis  Remittent fever:  Temperature remains above normal throughout the day and fluctuates more than 1 °C in 24 hours, e.g., infective endocarditis.  Intermittent Fever:  The temperature elevation is present only for a certain Period during the day, later cycling back to normal (i.e. Normal temp. between fever episodes), e.g. pyaemia, or septicemia. Internal Medicine - Tropical 1 Edited by: Co-MT team  Lecture 1 Approach to a case of fever and heat disorders  Relapsing Fever:  temperature returns to normal for days before rising –Tertian fever (48 hour periodicity), typical of Plasmodium vivax or Plasmodium ovale malaria  Pel-Ebstein fever:  A specific kind of fever associated with Hodgkins lymphoma, being high for one week and low for the next week and so on. However, there is some debate as to whether this pattern truly exists. Presentation of Fever Feeling hot  A feeling of heat does not necessarily imply fever Rigors.  profound chills accompanied by chattering of the teeth and severe shivering and implies a rapid rise in body temperature. Excessive sweating.  Night sweats are characteristic of tuberculosis, but sweating from any cause is usually worse at night. Headache  Fever from any cause may provoke headache. Severe headache and photophobia, may suggests meningitis Delirium  Mental confusion during fever is well described and relatively more common in extreme of age. Muscle pain  Myalgia is characteristic of Viral infections such as influenza, Malaria and brucellosis Approach to the Febrile Patient A) History taking:  The most important step to evaluate a febrile patient is to take a thorough and meticulous history to explore problems of the patient from different perspectives such as, the chronology of symptoms, patient’s perspective and review of each system to appropriately localize the source of the fever. Internal Medicine - Tropical 2 Edited by: Co-MT team  Lecture 1 Approach to a case of fever and heat disorders 1- Symptom analysis for fever:  Verify presence of fever- True or factitious fever  Duration- Acute or chronic  Mode of onset- Abrupt or gradual  Progression- Continuous or intermittent. If intermittent ask about frequency to determine the pattern.  Severity- how it affects daily work/physical activities.  Relieving and aggravating factors  Treatment received or/and outcome  Associated symptoms Localizing symptoms may indicate the source of fever. 2- Pattern of temperature changes:  discussed previously 3- Chills and rigors:  Rigors are profound chills accompanied by chattering of the teeth and severe shivering, implies a rapid rise in body temperature, it is mainly seen in malaria, sepsis with abscess, cholangitis and pyelonephritis. 4- Night sweats:  Night sweats are characteristic of lymphoma and tuberculosis. 5- Headache and Delirium:  Fever from any etiology may provoke headache. Severe headache and altered sensorium in a febrile patient ay point towards more ominous causes such as, meningitis and encephalitis. 6- Muscle pain :  Myalgia is seen in infections such as influenza, dengue fever, malaria, leptospirosis and scrub typhus. 7- Respiratory tract symptoms : 1. Sneezing, sore throat, purulent nasal discharges are suggestive of upper respiratory tract infection. 2. Pain over the sinus and headache suggests sinusitis 3. Cough, sputum, respiratory distress or wheezing suggests a lower respiratory tract infection. Internal Medicine - Tropical 3 Edited by: Co-MT team  Lecture 1 Approach to a case of fever and heat disorders 8- Genitourinary symptoms :  frequency of micturition, burning sensation, loin pain suggests urinary tract infection.  Associated vaginal or urethral discharge indicates sexually transmitted infection (STI) or pelvic inflammatory disease(PID). 9- Abdominal symptoms :  Presence of diarrhea, with or without blood in the stool, significant weight loss and pain abdomen point towards gastroenteritis, intra-abdominal infective foci, abdominal tuberculosis, inflammatory bowel disease (IBD) or malignancy. 10- Joint symptoms:  Pattern of joint involvement and number of joints involved are very important for diagnostic purpose.  Fleeting arthritis indicates rheumatic fever  Symmetric polyarthritis is associated with collagen vascular diseases and infective causes such a dengue and chikungunya. 11- Constitutional symptoms:  Weakness, anorexia, weight loss, fatigue, night sweats. 12- Fever with Generalized Lymphadenopathy:  Although the cervical group of lymph nodes are the most commonly afflicted nodes, but careful examination of all the other areas along with detailed evaluation of lymphoreticular system is of paramount importance to find out the underlying etiology.  Lymph node size of >1 cm in cervical or axillary and >1.5 cm in inguinal; any tender or matted node and lymphadenopathy of any size in supraclavicular or epitrochlear region should be considered as significant.  Tuberculosis and lymphoma are the two most common causes of generalized lymphadenopathy. Localized enlargement of lymph nodes is most likely due to local infection or malignancy. 13- Contextual History: 1) Any medical problems such as diabetes, asthma, heart disease, tuberculosis or jaundice. 2) Past history of surgery, intervention or transfusion. 3) Drug history (drug fever is common in penicillin, cephalosporin, sulphonamides, phenytoin and antituberculous agents), use of any herbal or alternative medicine and immunization history Internal Medicine - Tropical 4 Edited by: Co-MT team  Lecture 1 Approach to a case of fever and heat disorders 4) Personal and social history regarding addiction (smoking, alcohol, intravenous drug abuse), water supply and sanitation status, exposure to animals and birds, sexual history and dietary habits. 5) Travel history and occupational history. Examination Document the presence of fever A careful examination is vital and must be repeated regularly Particular attention should be paid to :  The skin ………….for skin rash  Throat…………….for pharyngitis  Eyes………………for jaundice , scleritis.  Nail bed ………….for clubbing, splinter hemorrhage.  lymph nodes…….. for enlargmant  abdomen …………for ascitis or sign of peritonitis  heart ……………...for murmurs indicating endocarditis Alteration in blood pressure:  Severe hypotension in febrile patients may indicate septic shock or acute meningococcal septicemia with adrenal involvement  Tachypnea:  In this present Coronavirus Pandemic, pyrexia with tachypnea and cough should be thoroughly evaluated and properly treated. Altered mental status:  Presence of altered mental function is an ominous sign and may indicate etiologies such as meningitis or encephalitis Mouth and oropharynx  Vesicular lesions, tonsillar exudate suggests Infectious etiology: 1) streptococcal pharyngitis 2) coxsakie infection  Hairy leukoplakia. OR oropharyngeal candidiasis suggest HIV /AIDS Oropharyngeal candidiasis.. Suggest Immunodefficiency syndrome Internal Medicine - Tropical 5 Edited by: Co-MT team  Lecture 1 Approach to a case of fever and heat disorders Eyes  Conjunctival petechiae may suggest meningococcal meningitis  Jaundice may suggest acute hepatitis A Cervical lymphnodes enlargment :  Tonsillar LN enlargmant suggest : Acute pharyngitis or tonsillitis  Posterior lymphadenopathy suggest : 1) Infectious mononucleosis 2) HIV infection  Axillary lymph node enlargement may suggest: 1) Sepsis 2) Leukemia 3) lymphoma  Joints (any joint but commonly the knee and ankle)  Look for swelling, redness, hotness and effusion suggesting active arthritis..? infective/septic arthritis Neck  look for stiffness..may suggest meningitis Abdomen:  Look for : Tenderness( especially in the RIF)…& acute append.  other types of ac abdomen Chest and heart 1) Sign of consolidation 2) Pleural effusion 3) Pericardial rub 4) Cardiac murmur………Endocarditis or acute rheumatic fever 1) Laboratory investigations: A. Complete blood count (CBC) with differential  Complete blood count with differential,  band forms and toxic granulation..suggest bacterial infection  Neutropenia : may be seen with Infection like Typhoid, brucellosis ,viral infection. Also seen in vasculitis like systemic lupus erythromatosis  lymphocytosis : may be seen in TB, brucellosis and in Viral infectious diseases. Internal Medicine - Tropical 6 Edited by: Co-MT team  Lecture 1 Approach to a case of fever and heat disorders  Monocytosis: may be seen in TB, typhoid , brucellosis and in lymphom  Eosinophilia may be seen in: a) Hypersensitivity drug syndrome b) Hodgkin disease c) Adrenal insufficiency  blood films may be done to exclude some parasites like malaria and trypanosoma Urine analysis Samples from any fluid and examine like pleural, peritoneal or even joint effusion. Bone marrow aspirate & biopsy for microbiologic and histopathology. Stool analysis Sputum evaluation : a) gram staining b) Z-N staining for acid fast bacilli Culture for: blood, abnormal fluid collection and urine CSF: if meningitis is suspected such as gram stain and culture Blood chemistry: electrolytes , glucose, urea , and liver functions HIV screening 2) Radiology: A. Chest X ray Posterior-anterior (PA) and lateral views should be taken on all patients with unexplained fever. B. Abdomen.  Flat and upright X-ray views may be useful when the patient has a fever and abdominal pain.  Be sure to look for air-fluid levels, bowel distention, kidney stones, and free air.  Abdominal ultrasound is often inadequate for ruling out intra-abdominal abscesses and other pathology but may be better than a CT scan for evaluating the gallbladder and bile ducts specifically (e.g., cholecystitis or ascending cholangitis) Treatment  If a potentially dangerous infection is suspected, or close follow-up is uncertain, admission to the hospital is warranted.  Older adults, patients that are immunocompromised, or patients with other organ system disease may also require admission. Internal Medicine - Tropical 7 Edited by: Co-MT team  Lecture 1 Approach to a case of fever and heat disorders A. General measures 1- Fluids need to be administered to keep up with increased insensible losses. 2- Discontinuing medications that may be responsible for a fever can be both diagnostic and therapeutic. B. Empiric antibiotic therapy 1) Nontoxic patients who are otherwise stable may be closely watched without antibiotics, until a diagnosis is made. 2) Patients hospitalized for fever and neutropenia, suspected meningitis, or who are critically ill should be treated empirically pending culture results. 3) A low threshold for giving empiric antibiotics should also be used for patients who are immunocompromised, (including those with HIV infection, diabetes, alcoholism, or liver or renal disease), and patients who are asplenic or taking steroids or immunosuppressants. In such patients, delaying antibiotics can become life- threatening. 4) Empiric antibiotic coverage should be appropriately narrowed after a source of infection has been identified or should be discontinued if infection is excluded. C. Antipyretic therapy 1. Acetaminophen (325–650 mg every 4 hours as needed)  is given initially to provide symptomatic relief. It should preferentially be administered in response to fever rather than around-the-clock so that the temperature curve can be monitored. 2. Ibuprofen (400–800 mg every 8 hours) and cold sponge baths  may be useful for persistent fevers. 3. Evaporative cooling is often used for patients with a temperature greater than 41° C.  In this technique, the patient is sprayed with cool water while fans move ambient air across the body. Electric cooling blankets can be used as well. Internal Medicine - Tropical 8 Edited by: Co-MT team