Cardinal Manifestations of Disease: ALTERATIONS IN BODY TEMP.

Dr. Gerrard Dennis Uy

Fever and Hyperthermia

• hypothalamic thermoregulatory center – regulates body temperature (core BT 37 C)

• A.M. temperature of >37.2°C (>98.9°F) or a P.M. temperature of >37.7°C (>99.9°F) would define a fever

• Rectal temperatures are generally 0.4°C (0.7°F) higher than oral readings

Fever• Elevation of body temperature that

exceeds the normal daily variation• occurs in conjunction with an increase in

the hypothalamic set point• Vasoconstriction in hands and feet shunts

blood to the internal orgrans• shivering = heat conversion and

production• until the temperature of the blood

bathing the hypothalamic neurons matches the new thermostat setting

Fever

• Pathogenesis– Pyrogen – any substance that causes fever• Exogenous (microbial products, microbial toxins, or

whole microorganisms)– E.g. LPS endotoxin – gram negative bacteria

• Endogenous a.k.a Pyrogenic cytokines (IL-1, IL-6, tumor necrosis factor (TNF), ciliary neurotropic factor (CNTF), and interferon (IFN) )

– Elevation of Hypothalamic Set point• levels of prostaglandin E2 (PGE2) are elevated in

hypothalamic tissue and the third cerebral ventricle

Hyperthermia

• uncontrolled increase in body temperature that exceeds the body's ability to lose heat

• setting of the hypothalamic thermoregulatory center is unchanged

• does not involve pyrogenic molecules• Exogenous heat exposure and endogenous

heat production

Hyperthermia

• Can be rapidly fatal• Does not respond to antipyretics

The Decision to Treat Fever

• Most fevers are associated with self limiting infections

• There is no significant clinical evidence that antipyretics delay the resolution of viral or bacterial infections nor there is evidence that fever facilitates recovery from infection

• Fever can provide important diagnostic clues in different disease conditions

The Decision to Treat Fever

• The objective in treating fever is to reduce the elevated set point and to facilitate heat loss

• Reducing fever also reduces systemic symptoms

• Treatment of fever in some patients is highly recommended (cadiac, cerebrovascular, and pulmonary diseases)

Mechanism of antipyretics

• Acts by reducing the level of PGE2• Common antipyretics– Acetaminophen– Aspirin– NSAIDS– glucocorticoids

FEVER and RASH

Approach to the patient with fever and rash

• A thorough history if often needed• Includes:– Immune status– Medications taken within the previous month– Travel history– Immunzation status– Exposure to domestic pets– Recent exposure to ill individuals

• The history should also include onset and direction and rate of spread

Types of lesions• Macules - flat lesions defined by an area of changed color • Papules - raised, solid lesions <5 mm in diameter• plaques ->5 mm in diameter with a flat, plateau-like surface• nodules ->5 mm in diameter with a rounded configuration• Wheals (urticaria, hives) - papules or plaques that are pale

pink and may appear annular (ringlike) as they enlarge• Vesicles (<5 mm) and bullae (>5 mm) are circumscribed,

elevated lesions containing fluid• Pustules are raised lesions containing purulent exudate

Types of lesions

• Nonpalpable purpura: - flat lesion that is due to bleeding into the skin.– <3 mm --- petechiae– >3 mm --- ecchymoses

MACULES

PAPULES

PLAQUES

NODULES

PUSTULES

WHEALS

VESICLES

BULLA

PETECHIAE

ECCHYMOSES

RUBEOLA

• Also known as measles/first dse• Caused by paramyxovirus• rash starts at the hairline 2–3 days into the

illness and moves down the body, sparing the palms and soles

• Associated with cough, conjunctivitis, coryza, and severe prostration

• Koplik's spots - seen during the first 2 days

RUBEOLA

• Infection is spread by contact with droplets from the nose, mouth, or throat of an infected person

• Sneezing and coughing can put contaminated droplets into the air.

• Resolves spontaneously after 1-2 weeks

RUBELLA

• also known as German measles/3rd disease or 3 day measles

• Caused by togavirus• also spreads from the hairline downward, but

tend to clear from originally affected areas as it migrates, and it may be pruritic

• Usually accompanied by postauricular, suboccipital and posterior cervical lymphadenopathy

RUBELLA

• Forschheimer spots – red spots (petechiae) seen on the soft palate in 20% of patients– Not diagnostic of rubella

ERYTHEMA INFECTIOSUM

• also known as the fifth disease • Caused by human parvovirus B19• primarily affects children 3–12 years old• develops after fever has resolved as a bright

blanchable erythema on the cheeks (slapped cheek appearance) – more diffuse rash (often pruritic) appears the next day

on the trunk and extremities and then rapidly develops into a lacy reticular eruption that may wax and wane over 3 weeks

ERYTHEMA INFECTIOSUM

• Only supportive treatment• No known complications

SLE

• typically develop a sharply defined, erythematous eruption in a butterfly distribution on the cheeks (malar rash)

• Etiology is autoimmune

Still’s Disease

• Juvenile rheumatoid arthritis• manifests as an evanescent salmon-colored

rash on the trunk and proximal extremities that coincides with fever spikes

• Etiology unknown

Fever of Unknown Origin (FUO)

Classic Definition• 1) temperatures of >38.3°C (>101°F) on

several occasions• (2) a duration of fever of >3 weeks• (3) failure to reach a diagnosis despite 1 week

of inpatient investigation

Fever of Unknown Origin

New Classification• (1) classic FUO• (2) nosocomial FUO• (3) neutropenic FUO• (4) FUO associated with HIV infection

Classic FUO• temperatures of >38.3°C on several occasions• a duration of fever of >3 weeks• 3 outpatient visits or 3 days in the hospital

without elucidation of a cause or 1 week of "intelligent and invasive" ambulatory investigation

• CAUSES: – Undiagnosed – 30%– Infections (e.g. Tuberculosis) – 26%– Non-infectious Inflammatory (e.g.PR, SLE)– 24%– Neoplasms – 12.5%

FUO

• Nosocomial FUO – more than 50% are infected– Intravascular lines, septic phlebitis, and

prostheses are all suspect– Multiple blood, wound, and fluid cultures are

mandatory– Threshold for CT scans, ultrasonography, 111In

WBC scans, noninvasive venous studies is low

FUO

• Neutropenic FUO - neutrophil coun < 500/ul– Neutropenic patients are susceptible to focal

bacterial and fungal infections, to bacteremic infections, to infections involving catheters (including septic thrombophlebitis), and to perianal infections

– Candida and Aspergillus infections are common– 50–60% of febrile neutropenic patients are

infected, and 20% are bacteremic

FUO

• HIV- associate FUO– Due to HIV alone– due to Mycobacterium avium or Mycobacterium

intracellulare, tuberculosis, toxoplasmosis, CMV infection, Pneumocystis infection, salmonellosis, cryptococcosis, histoplasmosis, non-Hodgkin's lymphoma, and (of particular importance) drug fever

Hypothermia and Frostbite

• Accidental hypothermia - unintentional drop in the body's core temperature below 35°C

• Primary accidental hypothermia is a result of the direct exposure of a previously healthy individual to the cold

• Secondary hypothermia is a result from complication of a serious disorder

Hypothermia

• Causes:– Climate– Endocrine dysfunction– Adrenal insufficiency– Hypopituitarism– Neurologic injury– sepsis

Hypothermia

• Heat loss occurs through five mechanisms: – radiation (55–65% of heat loss)– conduction (10–15% of heat loss, but much

greater in cold water)– convection (increased in the wind)– Respiration– evaporation (which are affected by the ambient

temperature and the relative humidity)

Hypothermia• Hypothermia is confirmed by measuring the core

temperature, preferably at two sites.– Rectal probes should be placed to a depth of 15 cm– Simultaneous esophageal probe placed 24 cm below

the larynx• cardiac monitoring should be instituted, along

with attempts to limit further heat loss• Supplemental oxygenation is always warranted• NGT, FBC• Establish IV line with warm saline

BACK AND NECK PAIN

Anatomy Review

• Anterior portion of the spine consist of cylindrical vertebral bodies separated by intervertebral disks

• The disks are responsible for 25% of spinal column strength

• The function of the anterior spine is to absorb shock of body movements

Anatomy Review

• The posterior portion of the spine consists of the vertebral arches and seven processes

• The function of the posterior spine is to protect and spinal cord and nerves and to stabilize the spine by providing sites for attachments of muscles and ligaments

• Nerve root injury (radiculopathy) is a common cause of neck, arm, and low back and leg pain

• Pain sensitive structures in the spine:– Periosteum of the vertebra– Dura– Facet joints– Annulus fibrosus– Epidural veins– Posterior longitudinal ligaments

Types of back pain

• Local Pain– Caused by stretching of pain sensitive structures

that compress or irritate sensory nerve endings

• Pain referred to the back– May arise from abdominal or pelvic viscera– Usually unaffected by posture– Nonspecific back pains

Types of back pain

• Pain of spine origin– Diseases affecting the upper lumbar spine tend to

refer pain to the lumbar region, groin, or anterior thighs

– Diseases affecting the lower lumbar spine tend to refer pain to the buttocks, posterior thighs, calves

• Radicular back pain– Sharp and radiates from the lumbar spine to the leg– Pain may increase in postures that stretch the nerves

and nerve roots

Examination of the back

• Straight leg – raising test (SLR test):– Also called lasegue test– to determine whether a patient with low back

pain has an underlyingherniated disk, mostly located at L5

– With the patient lying flat, passive flexion of the extended leg at the hip stretches the L5 and S1 nerve roots and the sciatic nerve

– Positive if the maneuver reproduces the usual back or limb pain

Examination of the back

• Crossed SLR sign– Less sensitive but more specific for disk herniation– Positive when flexion of one leg reproduces the

pain in the opposite leg or buttocks• Reverse SLR sign– Elicited by standing the patient next to the

examination table and passively extending each leg with the knee fully extended

– Positive if the patient’s usual back or limb pain is reproduced

Common Causes of Back Pain

• Congenital Anomalies:– Spondylosis:

• A bony defect of the vertebra• Usually bilateral• Most common cause of persistent low back pain in

adolescents• Often activity related

– Spondylolisthesis:• Anterior slippage of the vertebral body, pedicles, and

superior articular facets, leaving the posterior elements behind

• Occurs more frequently in women

• Congenital Anomalies cont– Spina bifida• Failure of closure of one or several vertebral arches

posteriorly• The meninges and spinal cord are normal

– Tethered cord syndrome• Usually presents as a progressive cauda equina

disorder• Patient is often a young adult who complains of

perineal or perianal pain

Common Causes of Back Pain

• Trauma– Patients may have a spinal fracture or dislocation

• Sprains and Strains– Usually minor self limiting injuries associated with

lifting a heavy object, a fall, or a sudden deceleration

– Pain is usually confined to the lower back– No radiation present

Common Causes of Back Pain

• Lumbar Disk Disease– Most likely to occur at the L4-L5 and L5-S1 levels– Cause is unknown– Risk is increased in overweight individuals– Degeneration of the nucleus pulposus and annulus

fibrosus increases with age– Pain is usually located in the low back and maybe

referred to the leg, buttock, or hip

Neck

• Neck pain usually arises from diseases of the cervical spine and soft tissues of the neck

• Causes of neck pain:– Trauma– Cervical Disk Disease– Cervical Spondylosis

Cervical Disk Disease

• Presents with neck pain, stiffness, and limited range of motion

• Spurling’s Sign – extension and lateral rotation of the neck reproduces symptoms

• Cervical disk herniations are usually posterolateral

• For the next meeting, read on Cardinal Manifestations of Disease : DYSPNEA

• Harrison’s Principles of Internal Medicine 17th edition