Unit 1 - Fever and Malignancy Flashcards
definition of fever
elevation in core body temperature from resetting of thermostatic regulatory system caused by pyrogens
what is normal temperature and fever quatitatively?
normal: 36.8 C (+/- 0.4) –> 37 C or 98.6 F
fever: > 38.4 C or > 101 F
what are pyrogenic cytokines to keep in mind?
IL-1, IL-6, TNF, IFN
what does a continuous fever mean?
fever all day and does not fluctuate more than 1 degree C in 24 hours (in bacterial infections)
what does intermittent/recurrent fever mean?
temperature elevation cycles (in malaria, bacterial septicemia, obstruction of calculi causing UTI and cholecystitis)
what does remittent fever mean?
temperature above normal all day, fluctuates more than 1 C in 24 hours (in endocarditis)
what are critical (noninfectious) diagnoses to consider with acute fever?
AMI or CVA PE/DVT intracranial hemorrhage neuroleptic-malignant syndrome thyroid storm acute adrenal insufficiency transfusion reaction pulmonary edema sickle cell crisis transplant rejection pancreatitis
what is an FUO defined as and what are its common points?
fever of unknown origin is elevated body temperature persisting for more than 3 weeks without diagnosis, despite 1 week of investigations at the hospital
- majority of illnesses are treatable, and are from a common disease presenting atypically
- as duration of fever increases, likelihood of infectious cause decreases
etiology of FUO
30% infections 20% malignancy 15% CT disorders 20% miscellaneous 15% unknown
4 DDx of fever
- infectious (tyhpoid, hepatitis A/B, leptospirosis, TB, malaria)
- malignancies (leukemia, lymphoma)
- autoimmune conditions, joint/CT disease (RA, rheumatic fever, SLE, vasculitis)
- others (drug induced fever, IBD, hypothalmic lesions)
what are the common FUO infections in adults?
abscess and TB
what is the most common cause of FUO in kids?
infections
explain the importance of septicemia with negative blood cultures
in proven bacterial endocarditis; up to 5% of cultures can remain negative despite figorous collection techniques due to:
- prior administration of antibiotics
- severe local infection (intra-abdominal, mixtures of aerobic and anaerobic bacteria)
- fastidious, slow-growing organism in blood
- infections due to organisms not routinely cultured (TB, fungus)
- toxemia - toxic shock syndrome
what are night sweats a characteristic of?
TB and malignancy
what are constitutional symptoms?
weakness, fatigue, anorexia, weight change, fever/chills, lumps, night sweats
explain facitious fever
engineered by patient by manipulating thermometer and/or temperature chart
- uncommon, but mostly in young women with medical/nursing background
- clues are:
- -patient appears well
- -absence of temperature-related changes in pulse rate
- -temps > 41 C (falsely high)
- -absence of sweating during period of fever
- -normal ESR and CRP
what are three things to take into account for history?
- chronology
- contextual history
- patient’s perspective
what does it mean when someone has rigors/shaking chills?
profound chills with chattering of teeth and severe shivering implies rapid rise in body temperature
-sepsis with abscess, lymphoma, malaria
what are associated symptoms in chronology of fever?
- respiratory tract: upper or lower RTI, sinusitis, cough, sputum, wheeze, shortness of breath
- genitourinary: dysuria, increased frequency of urination, vaginal/urethral discharge, UTI, PID, STI
- abdominal symptoms: diarrhea with/without blood, weight loss and abdominal pain (gastroenteritis, intra-abdominal sepsis, IBD, malignancy)
- constitutional symptoms
what is headache/photophobia associated with?
meningitis (if severe)
what is delirum associated with?
mental confusion during fever is more common in young children and old age
what is myalgia associated with?
characteristic of viral infections like influenza and malaria
what do macular rashes + fever mean?
measles, rubella, toxoplasmosis, EBV
what do hemorrhagic/petechiae rashes + fever mean?
meningococcal infections, viral hemorrhagic fever, Neisseria
what do vesicular rashes + fever mean?
chickenpox, shingles, herpes simplex
what do nodular rashes + fever mean?
erythema nodosum (usually drugs), TB, leprosy
what do erythematous rashes + fever mean?
drug rashes
what do joint symptoms mean?
pain or swelling suggests reactive arthritis, mono or polyarticular
explain drug fever and common culprits
relatively uncommon, and easily missed
- penicillins and cephalosporins
- sulphonamides
- antiepileptics
- anti-TB agents
what is the usual timeframe for fevers from drugs?
kicks in anywhere from 5 to 14 days after beginning to take drug
if someone has a fever every third day, what is the most likely DDx?
malaria
