Case 11. A baby is born with a rash identical to that seen in

Transcription

1 Case 11. A baby is born with a rash identical to that seen in the baby. Questioning reveals that the mother had a febrile illness during the second trimester of pregnancy. Examination reveals diffuse raised purple skin lesions. There is no pallor, jaundice, or cyanosis. The eyes are normal externally, the heart has a 3/6 systolic murmur, and there is enlargement of both the liver and the spleen. There is no LAP. ١

2 What is your differential diagnosis? What would you like to know? ٢

3 CHEAP TORCHES: C: Chickenpox H: Hepatitis B/C/E E: Enterovirus A: AIDS (HIV) P: Parvovirus B19 T: Toxoplasmosis O: other (GBS, Listeria, Candida,T.B, LCMV) R: Rubella C: CMV H: HSV E: Everything else STD (gonorrhea, Chlamydia, ureaplasma, HPV) S: Syphilis ٣

4 In this case the rash was caused by rubella. The CRS may be associated with abnormalities affecting many organs: Ocular: cataract, microphthalmia, corneal opacity Ear: deafness Heart: CHD Brain:Microcephaly Liver: Hepatitis B.M: Anemia/ Thrombocytopenia Bone: Linear Lucencies in long bones ( celery stalk appearance) ٤

5 The usual methods used to diagnose intrauterine infection infection Rubella CMV HIV LCMV Syphilis Toxo Method serology PCR on blood, urine viral culture DNA PCR Serology serology(pcr) Serology ٥

6 CASE 12. A 6 y/0 girl complains of weakness and muscle pain and tightness in her thighs and legs. About 1WK earlier she had a fever, sore throat, and cough. On examination she can t stand nor walk due to weakness. Her thighs and calves are tender. Sensation and DTR are NL. Examination of the back and upper limbs is N.L. What might be wrong with her? What would you like to know? ٦

7 The DD X is one of generalized weakness but preserved higher function. This suggests a lower motor neuron lesion affecting her lower limbs. The possible levels of disease should be considered anatomically. It is useful to consider possible etiologies of disease for each of these sites. The DD X should include the infectious and noninfectious disease. ٧

8 Causes of acute flaccid weakness : (A) Spinal cord : spinal shock/ transverse myelitis (B) Ant. Horn cell: polio/ other enterovirus/ WNV (C) Peripheral nerve: GBS/ Diphtheria/ toxins/ Acute intermittent porphyria (D) Neuromuscular junction: botulism/ snake bites (E) Muscle: myositis/ electrolyte disturbance (F) Pseudo paresis (localized) : skeletal disease/ trauma/ osteomyelitis/ septic arthritis/ congenital syphilis (G) Unknown mechanism: tick paralysis ٨

9 The pain and muscle tenderness in this patient indicate muscle inflammation (myositis) as the cause of the weakness. Acute muscle disease may be due to injury, inflammation (myositis), or a metabolic disorder, d for example, heat stroke. Acute myositis ii is usually caused by a viral infection such as influenza, enterovirus, HIV. This is referred to as benign acute childhood myositis, which is to be distinguished from the myositis accuring with dermatomyositis or polymyositis, which have a prolonged course and can result in significant long term disability. Patient with benign acute myositis present with acute onset of weakness and muscle pain and tenderness, must frequently affecting the calf muscles. The muscles may be swollen and the weakness may be profound. The dangers of myositis are respiratory failure and rhabdomyolysis. y ٩

10 The diagnosis of myositis can be confirmed by the demonstration of elevated CPK activity in the serum. Myoglobinuria manifests as red, clear urine (like rose wine) as opposed to red, cloudy urine that occurs with hematuria. In this circumstance a urine dipstick test that is positive for blood in the absence red cells on microscopy is highly suggestive of myoglobinuria. A microbiological diagnosis of the cause of myositis is not usually helpful, unless HIV infection is suspected. Treatment is primarily supportive, entailing analgesia and a very high fluid intake. If myoglobinuria is present the urine should be alkalinized to prevent injury to the renal tubules. Monitoring of respiratory function is essential. ١٠

11 Case 13. A 6 month old boy presents with watery diarrhea and a tem. : 38.5 /c What is the most important t aspect of the clinical i l evaluation? What is the likely clinical diagnosis, and what are its possible causes? What do you want to do? ١١

12 The most important question addresses the physiologic diagnosis, namely: what is his hydration status? The sign of dehydration are: Decreased urine output Sticky oral mucosa Decreased skin turgor Sunken eyes Tachycardia Poor peripheral perfusion and L.O.C. (shock) what is the likely diagnosis? This is most likely a case of acute infectious diarrhea (acute GE). The possible causes are listed in next slide. ١٢

13 Causes of acute infectious diarrhea Virus: Rota, Adeno., Noro., Astro. Bacteria: salmonella, shigella, campylobacter, E. coli, yersinia, vibrio cholera, vibrio parahaemolyticus, clostridium difficile, clostridium perfringens Parasites: giardia, C. Parvum, cyclospora, I. belli, E. Histolytica, B. coli ١٣

14 Complications: 1. Dehydration 2. Metabolic and electrolyte disturbances 3. Bacteremia 4. HUS 5. Toxic encephalopathy 6. Chronic diarrhea 7. Colonic perforation 8. Reactive arthritis 9. GBS ١٤

15 Causes of altered mental status in children who have or have had diarrhea Shock from dehydration Metabolic and electrolyte disturbance Hypoglycemia Hyperglycemia Hyponatremia Hypernatremia Vascular Stroke HUS Iatrogenic (rapid correction of hypo/ hyper natremia) Complication of bacteremia (meningitis) shigellosis ١٥

16 Differential diagnosis of intestinal symptoms and signs Vomiting, no diarrhea Gastritis Food poisoning Raised ICP Intestinal obstruction (intussusception) Parental infection Hematochezia, no diarrhea Meckel s diverticulum Intussusception Polyp Profound upper intestinal bleeding Bloody diarrhea Milk protein allergy IBD ١٦

17 Epidemiological, clinical, and stool features associated with different enteric infection, and tests used for their confirmation Microorganism epidemiology clinical stool test Rotavirus winter acute no blood Ag Adenovirus acute no blood tissue culture Norovirus outbreak acute, vomiting no blood RT PCR Salmonella animals, eggs, meat acute, fever ± blood, PUS culture Shigella day care, human acute, fever ± blood, PUS culture Campylobacter poultry acute ± blood, PUS culture yersinia i pork acute ± blood culture Giardia daycare, water acute, chronic no blood micro./ Ag cryptosporidium water, outbreak acute, chronic no blood micro./ Ag Cyclospora outbreak acute, chronic no blood micro E. Histolytica travel acute, chronic blood micro. /Ag ١٧

18 Antimicrobial i therapy of enteric infections Microorganism antimicrobial agents Salmonella none, unless bacteremia suspected ceftriaxone, TMP/S Shigella ampicillin, TMP/S, ceftriaxone azithromycin, fluoroquinolone Campylobacter jejunij azithromycin, ih i fluoroquinolone l gentamicin, imipenem Yersinia enterocolitica none, unless bacteremia suspected ceftriaxone, e, TMP/S, gentamicin E. Coli TMP/S, Flouroquinolone, rifaximin C. Difficile metronidazole, oral vancomycin Giardia metronidazole, nitazoxanide C. Parvum nitazoxanide id Cyclospora TMP/S I. Belli TMP/S E. Histolytica metronidazole, tinidazole ١٨

19 Case 14. A premature infant in the NICU being ventilated for HMD is noted to have temperature instability, dark red spots on the skin, and a swollen red ankle. Further examination reveals a 3/6 ejection systolic heart murmur, heard loudest at the upper sternal border. She has a venous and arterial vascular catheter in place. The abdominal examination is NL. What is the differential diagnosis? What would you do? ١٩

20 Dark red spots on the skin suggest the possibility of hemorrhage or infarctions of the skin. The red, swollen ankle suggests a septic arthritis or osteomyelitis. Tem. Instability suggests a systemic infection. A unifying diagnosis would be a systemic (bloodstream) bacterial or fungal infection associated with skeletal infection, and causing (a) a hemorrhagic tendency through the mechanisms of thrombocytopenia or DIC or (b) emboli due to IE. Nosocomial infection is important. The potential routes of infection are through: Vascular access sites Lungs (intubation) Intestine U.T.I *** Staph./ enterococci/ candida/ gram neg. bacilli ٢٠

21 Specific clinical evaluation Examination of the optic fundi Examination of all vascular access sites U/A B/C, CBC Aspiration of ankle / skin lesions (gram stain/ culture) Echo. ٢١

22 Antimicrobial treatment (a) Gram positive cocci (staph.): vancomycin+nafcillin+gentamicin. The reason for using both vancomycin and nafcillin is that for susceptible organisms,, nafcillin is superior to vancomycin. However, the vancomycin is necessary in case the organism is resistant to β lactam AB (MRSA). Gentamicin accelerates the clearance of the staph. from the blood. (b) Gram negative rods (enteric bacilli or p. aeruginosa): ceftazidime + amikacin/ gentamicin (c) Yeasts: amphotericin B (in less severly ill patients with intravascular line associated fungemia, and without endocarditis, and in whom the vascular line can be removed, fluconazole would be appropriate. (d) If the gram stain does not reveal an ogranism, initial treatment should be directed at staph. and gram negative rods with vancomycin, nafcillin, gentamicin, or amikacin and a 3 rd generation cephalosporin. ٢٢

23 The gram stain from a skin aspirate of this patient shows gram positive cocci in clusters, the typical appearance of staphylococci. hl The skin, B/C, ankle joint fluid grew out staph. aureus susceptible to methicillin. Further evaluation revealed an aortic vegetation, providing additional evidence of IE. She was treated successfully with nafcillin. ٢٣

24 CASE 15. A 3 Y/O boy who broke out with chickenpox 5 days ago seems to be getting worse after initial improvement. He has a high fever, his skin is red all over, and he seems a little confused. What might iht be the problem? ٢٤

25 The most likely problem is that this boy has developed a complication of chikenpox. The most common complication is secondary bacterial infection of skin lesions with s. pyogenes or S. aureus. The child s illness is characterized by fever, confusion, and diffuse erythroderma. Given the apparent severity of the child s condition and the combination of clinical abnormalities, he probably has streptococcal/ staphylococcal TSS. ٢٥

26 Further clinical evaluation should be directed at determining the adequacy of his perfusion and at finding a septic focus that might be drained. This is very important in TSS. Management should entail the following: (a) Ensuring adequate perfusion with IV fluid and vasopressors, if necessary. (b) Draining any focus of pus and sending specimens for gram stain and culture; a B/C should also be performed (c) Antimicrobial therapy: vancomycin (MRSA) + oxacillin/ nafcillin/ cephazolin (strep. Pyogenes/ MSSA) + Clindamycin (halt toxin production) (d) I.V.I.G ٢٦