Showing posts with label Pediatrics. Show all posts
Showing posts with label Pediatrics. Show all posts

Wednesday, March 28, 2012

Diarrhea Disease


              General introduction

Concept    common disease in childhood

 

                  frequency and characters of stool

 

Ages          6m~2y      50% <1y

 

Seasons     viral origins—late autumn and spring beginning
           bacterial origins—summer

                   noninfectious diarrhea— every season

 

  Predisposing factor-1

Ø   Gastric acid secretion   , secretion and activity of enzyme  , quality and quantity of diet change quickly.

Ø   Water metabolism  ,tolerance of hydropenia  ,easy to body fluid disorder.

Ø   Nerves, endocrine, circulation, liver and renal function: not mature, easy to digestive tract function disorder.

 

 

Grow and develop   , demand for nutrients    , burden of the stomach and intestines   , easy to indigestion.

 

Artifical feeding: enteritis morbility 10 times higher

                              than breast feeding.

milk: nutritional ingredient destroyed

milk tool: disinfection.

 

 Ø   Rotavirus

Ø   Astrovirus

Ø   Calicivirus: Norwalk virus,  sapovirus

Ø   Enterovirus: Coxsackie virus, echovirus,  enteric adenovirus

Ø   Coronavirus: torovirus

 

o    Bacillus coli 

   enteropathogenic E. coli ………………………EPEC
    enterotoxigenic E. coli …………………………ETEC
    enteroinvasive E. coli …………………………..EIEC
    enterhemorrhagic E. coli ………………………EHEC
    enteroadherent aggregative E. coli ……………EAEC

 

o    Campylobacter jejuni, Yersinia enterocolitica, others

o    Fungi :blastomyces albicans

o    Protozoa (parasite) :giardia lamblia, amebic protozoa

 

Ø    Disorder intestinal function

Ø    Infect intestinal tract directly

Ø    Irritation of rectum (eg. bladder infection)

                                                     alteration of intestinal flora

Ø    Much antibiotics used          transport of carbohydrate

                                                     lactase

 

                                                     o   Dietary factors

*  quality and quantity of food (feeding starch and fat too early)

*  Allergic diarrhea: milk or bean

*  Primary and secondary disaccharidase deficiency

 

 

 

Ø    Osmotic diarrhea: much poorly absorbed and hyperosmotic solute

Ø    Secretory diarrhea: electrolytes hypersecretion

Ø    Exudative diarrhea: inflammatory states causing liquor exudation

Ø    Motility disturbance: dynamic abnormality of intestine

Ø    Noninfectious diarrhea: feeding factors

 

 

 o   Dehydration

o   Metabolic acidosis

o   Electrolytes disorder

Mild and severe  diarrhea

 

Ø    Mild: the times of stool and character change

      

    —— stool :frequency ,loose, liquid,

               color: yellow or greenyellow,

               smell: sour flavor, shape: egg soup 

   —— vomiting: seldom

   —— general  poisoning symptom: without

   —— dehydration, electrolytes abnormality

        and general toxicity symptoms': none

Mild and severe  diarrhea

Ø    Severe: accompany dehydration, electrolytes

    abnormality and  general toxicity symptoms

    — digestive tract symptom : diarrhea serious ,mucus blood  sample stool, anorexia, nausea, abdominal                    

      pain  and abdominal distention

 

 

 

    — general  poisoning symptom : lethargy, dysphoria,

                                            unconsciousness and coma

 

    — dehydration, electrolytes abnormality ,

          acid base  imbalance

       

 

      Severity clinical signs of dehydration

 

Ø    Vomiting and diarrhea :Alkalinity intestinal juice lost

Ø    Eat  :calorie  , malabsorption®lipoclasis ®keto-bodies

Ø    Hypovolemia®pachemia®blood flow slowly®

       hypoxia®  anaerobic glycolysis ® lactic acid

Ø    dehydration® blood flow  ®excluding acid   ®

       acid metabolic product

 

Ø    Dispirited, dysphoria, drowsiness, coma

Ø    Hypernea  (Kussmauls  breathing),exhalation cool

Ø    Expiratory gas smells ketone

Ø    Cherry lips

Ø    Nausea, vomit

 

K+  (potassium)<3.5mmol/L (normal: 3.5~5.5 mmol/L)

causes:

Ø    Excessive losses: vomit, diarrhea.

Ø    Inadequate intake.

Ø    Renal function of keeping kalium    ,it continues excluding kalium when with hypokalemia.

 

Ø    depressed

Ø    Tension of skeletal muscle ,tendon reflex,

       even respiratory muscle weakness

Ø    Tension of smooth muscle   , abdominal distention

       intestinal sound  or disappear

Ø    Myocardium excitability   , arrhythmia, ECG: T-wave

       is low or inversion, U-wave occurs, prolonged P-R

       interval and Q-T interval, ST section descending.

Ø    Baseosis

 

Ø     Ca2+﹤1.75mmol/L (7mg/dl) ;

       Mg2+﹤0.6mmol/L (1.5mg/dl).

 

Ø    Symptoms usually occur after dehydration and

      acidosis resolved, or fluid replacement.

Ø    Clinical manifestation: thrill, tetany, convulsion.

 

Ø    If convulsion hasn’t relieved after supplement

 

 

 

      calcium,  pay attention to hypomagnesemia.

 

 

 

Ø    Season: cool months (autumn and winter)

Ø    Age: 6m~2y

Ø    Symptom: fever, vomit, mild general toxicity symptoms.

Ø    Stool: frequency, amount, water; yellow-water or egg soup-like; a small amount of mucus.

Ø    Dehydration: mild/moderate,isotonic/hypertonic

Ø    Complication: convulsion, myocardium damaged.

Ø    Prognosis: self-limited, course: 3~8d.

Ø    Viral antigen detection: from stool.

 

Ø    Season: summer

Ø    Symptom: vomit and diarrhea, no obvious general toxicity symptoms.

Ø    Stool: water-like or egg soup-like, without mucus, blood or pus, no WBC (test under microscope).

Ø    Dehydration: dehydration, electrolyte and acid-base disorder usually occur.

Ø    Prognosis: self-limited, course: 3~7d.

 

Ø    Similar with bacillary dysentery.

Ø    Symptom: diarrhea with fever, nausea, vomit, abdominal pain, tenesmus. Severe general toxicity symptoms, e.g. ardent fever, consciousness change, even septic shock.

Ø    Stool: with mucus, blood and pus, smell of fish, with WBC (test under microscope).

Ø    Stool culture: pathogenic bacterium.

 

Ø    Pathogen: usually Blastomyces albicans.

Ø    Age: ﹤2y.

Ø    Complication by other infection, or after using antibiotics for long time.

Ø    Persistent course, usually thrush companion.

Ø    Stool: yellow thin stool, more foam with mucus, sometimes tofukasu-like.

Ø    test under microscope: fungal spore and hypha.

 

 

Ø    Gastric mucosa analosis ® bacterium and yeast fungus

Ø    Intestinal mucosa thinner®indigestion and malabsorption

Ø    Bacterium in upper small intestine ®enterocyte damaged

Ø    Dynamic abnormality of intestine.

Ø    Using antibiotics for long time.

Ø    Immune function defect ® liability to agents  

 

vicious cycle

 

 

o   Not difficult

o   According to clinical manifestation, laboratory tests and character of stool.

 

 

 

 

Ø    Usually ﹤6m, bloating, breast-feeding.

Ø    Usually with eczema.

Ø    Normal appetite, growth and developed.

Ø    After cofood addition, stool turns to normal.

Ø    A special type of lactose intolerance

 

Ø    Epidemiology character

Ø    Stool culture: a dysentery bacillus discovered

 

Ø    Symptom: ardent fever, severe toxicity symptoms, abdominal pain and distension, vomit frequently.

Ø    Stool: first, yellow thin or egg soup-like;

                then, red pasty or adsuki bean soup-like.

Ø    X-ray of abdomen: local aerate and expansion in  

                small intestine, intestinal wall pneumatosis.

 

 

*   Adjust and continue feeding,  not abrosia or

      restricting water, prevent malnutrition.

*   Prevent and cure dehydration.

*   Rational administration: proper antibiotics, microecosystem preparation, assist-digestive drugs, mucosa protectant, antivomit drugs. Usually disusing antidiarrheal.

 

*   Strengthen nursing, symptomatic treatment, prevent

      complications.

*   Fluid therapy (next week lesson)


Measles


 

 Measles is…

* an acute viral infection characterized by a maculopapular rash erupting successively over the neck, face, body, and extremitis and accompanied by a high fever.

                              ETIOLOGY

 Measles virus

*An RNA virus of the genus Morbillivirus in the family of Paramyxoviridae

*One serotype, human’s only host

*Stable  antigenicity

*Rapidly inactivated by heat and light

*Survival in low temperature.

                          EPIDEMIOLOGY

*Infection sources

n  Patients of acute stage and viral carriers of  atypical measles

*Transmission

n  Highly contagious, approximately 90% of susceptible contacts acquire the disease.

n  Respiratory secretions: maximal dissemination of virus occurs by droplet spray during the prodromal period (catarrhal stage).

n  Contagious from 5 days before symptoms, 5 days after onset of rash

n  Seasons: in the spring, peak in Feb-May

 

PATHOGENESIS AND PATHOLOGY

*Portal of entry

n  Respiratory tract and regional lymph nodes

n  Enters bloodstream (primary viraemia) è monocyte – phagocyte  system è target organs (secondary viraemia)

*Target organs

n  The skin; the mucous membranes of the nasopharynx,

          bronchi, and intestinal tract; and in the conjunctivae, ect

Resulting In-----

 

1) Koplik spots and skin rash: serous exudation and proliferation of endothelial cells around the capillaries

2) Conjunctivis

 

    

         

PATHOGENESIS AND PATHOLOGY

3) Laryngitis, croup, bronchitis :general inflammatory reaction

4) Hyperplasia of lymphoid tissue: multinucleated giant cells (Warthin-Finkeldey  giant cells) may be found

5) Interstitial pneumonitis: Hecht giant cell pneumonia.

6) Bronchopneumonia: due to secondary bacterial infections

7) Encephalomyelitis: perivascular demyelinization occurs in areas of the brain and spinal cord.

8) Subacute sclerosing panencephalitis(SSPE):

    degeneration of the cortex and white matter with intranuclear and intracytoplasmic inclusion bodies

 

CLINICAL MANIFESTATION

 

Typical Manifestation:

 

    patients havn’t had measles immunization, or vaccine failure with normal immunity or those havn’t used immune globulin

 

1. Incubation period (infection to symptoms) :

         6-18days (average 10 days)

 

2. Prodromal period:

n    3-4 days

n    Non-specific symptoms: fever, malaise, anorexia, headache

n    Classical triad: cough, coryza, conjunctivitis (with

      photophobia, lacrimation)

CLINICAL MANIFESTATION

        Enanthem (Koplik spots):

 

n  Pathognomonic for measles

n  24-48 hr before rash  appears

n   1mm, grayish white dots with

     slight, reddish areolae

n   Buccal mucosa, opposite the

     lower 2nd molars

n   increase  within 1day and spread

n   fade  soon after rash onset

CLINICAL MANIFESTATION

CLINICAL MANIFESTATION

     3. Rash period

          3-4days

         Exanthem:

           Erythematous, non-pruritic, maculopapular

n       Upper lateral of the neck, behind ears, hairline,

         face è trunk  arms and legs feet

 

n       The severity of the disease is directly related to

         the extent and confluence of the rash

,

CLINICAL MANIFESTATION

CLINICAL MANIFESTATION

CLINICAL MANIFESTATION

CLINICAL MANIFESTATION

   Temperature:

n     Rises abruptly as the rash appears

n     Reaches 40℃ or higher

n     Settles after 4-5 days – if persists, suspect secondary

       infection

    Coryza, fever, and cough:

n     Increasingly severe up to the time the rash has covered the

       body

    Lymphadenopathy (posterior cervical region, mesenteric) splenomegaly, diarrhoea, vomiting

          Chest X ray:

n    May be abnormal, even in uncomplicated cases

 

CLINICAL MANIFESTATION

 4. Recovery period

     3-4days

     Exanthem:

n      Fades in order of appearance

n      Branny desquamation and brownish discoloration

 

     Entire illness – 10 days

 

CLINICAL MANIFESTATION

CLINICAL MANIFESTATION

Atypical  Manifestation:

 

1.  Mild measles

n      In patients: administered immune globulin products during the incubation period and immunized against measles; in infants <8mo

n      Long incubation period  and short prodromal phase

n      Mild symptom

n      No Koplik spot

n      The rash tends to be faint, less macular, pinpoint

n      No branny desquamation and brownish discoloration  occur as the rash fades

n      No complications and short course

CLINICAL MANIFESTATION

2. Severe measles:

n    In cases with  malnutrition, hypoimmunity and secondary

      infection

n    Persistent  hyperpyrexia, sometimes with convulsions and even

      coma

     Exanthem:

n     Completely covered the skin

n     Confluent, petechiae, ecchymoses

n     The hemorrhagic type of measles (black measles), bleeding

       may occur from the mouth, nose, or bowel. disseminated

       intravascular coagulation (DIC) 

CLINICAL MANIFESTATION

CLINICAL MANIFESTATION

3. Atypical measles syndroma:

n     Recipients of killed measles virus vaccine, who later come in

        contact with wild-type measles virus.

n     Distinguished by high fever, severe headache, severe abdominal

        pain, often with vomiting, myalgias, respiratory symptoms,

        pneumonia with pleural effusion

      Exanthem:

n     First appears on the palms, wrists, soles, and ankles, and

        progresses in a centripetal direction.

n     Maculopapular è vesicular è purpuric or hemorrhagic.

n     Koplik spots rarely appear

 

CLINICAL MANIFESTATION

CLINICAL MANIFESTATION

4. Measles absent of rush

n     Immunodepressed, or passive immunized recently cases and

       occasionally in infants <9mo who have appreciable levels

       of maternal antibody

n     Non-specificity

n     Difficult to diagnosis

 

COMPLICATIONS

1. Respiratory Tract

*  Laryngitis, tracheitis, bronchitis – due to measles itself

*  Laryngotrachobronchitis (croup) –cause airway obstruction to require tracheostomy

*  Secondary pneumonia – immunocompromised, malnourished patients. pneumococcus, group A

      Streptococcus, Staphylococcus aureus  and

      Haemophilus influenzae type B.

*  Exacerbation of TB

COMPLICATIONS

   2. Myocarditis

 

   3. Malnutrition and Vitamin A deficiency

COMPLICATIONS

    4. CNS

*The incidence of encephalomyelitis is 1-2/l,000 cases of measles

*Onset occurs 2-5 days after the appearance of the rash

*No correlation between the severity of the rash illness and

      that of the neurologic involvement

n    Earlier - direct viral effect in CNS

n    Later – immune response causing demyelination

n    Significant morbidity, permanent sequelae – mental

      retardation and paralysis

*Subacute sclerosing panencephalitis (SSPE): extremely rare, 6-10 years after infection. Progressive dementia, fatal. Interaction of host with defective form of virus

 

LABORATORY EXAMINATION

*Isolation of measles virus from a clinical specimen (e.g., nasopharynx, urine)

*Significant rise in measles IgG by any standard serologic assay

*Positive serologic test for measles IgM antibody

*Immunofluorescence detects Measles antigens

*Multinucleated giant cells in smears of nasal mucosa

 

*Low white blood cell count and a relative lymphocytosis in PB

*Measles encephalitis – raised protein, lymphocytes in CSF

 

DIAGNOSIS

characteristic clinical picture:

    Measles contact

    Koplik spot

    Features of the skin rash

    The relation between the eruption and fever

 

    Laboratory confirmation is rarely needed

 

DIFFERENTIAL DIAGNOSIS

*The rash of measles must be differentiated from that of

*rubella;

*roseola intantum;

*enteroviral  infections;

*scarlet fever;

*and drug rashes.

 

 

 

DIFFERENTIAL DIAGNOSIS

DIFFERENTIAL DIAGNOSIS

TREATMENT

*Supportive, symptom-directed

         Antipyretics for fever

         Bed rest

         Adequate fluid intake

         Be protected from exposure to strong light

*Antibiotics for otitis media, pneumonia

*High doses Vitamin A in severe/ potentially severe measles/ patients less than 2 years

        100,000IU—200,000IU

 

PREVENTION

*1. Quarantine period

      5 days after rash appears, longer for complicated measles

*2. Vaccine

      The initial measles immunization is recommended at 8mo of

         age

         A second immunization is recommended routinely at 7yr of

         age 

*3. Postexposure Prophylaxis

       Passive immunization with immune globulin (0.25mL/kg)

       is effective for prevention and attenuation of measles within

         5 days of exposure.