差分

====intestinal====*can mimic Crohn's disease*most common in ileocecal====meningitis====*often involves 3rd and 6th cranial nerves*meningeal irritation signs often unaccompanied====cerebral tuberculoma====*DDx primary CNS lymphoma====Pott's disease (vertebral destruction due to TB)====*kyphosis, gibbus formation*sometimes extends to psoas muscle abscess; ====arthritis====*synovial fluid does not necessarily contains enough TB bacteria; fluid culture may miss diagnosis*IGRA could be clue===skin===*erythema nodosum **DDx - TB, cryptococcal, sarcoidosis, UC, oral contraceptive, &asymp;50% idiopathic*lupus vulgaris===miliary TB===**massive lymphohematogenous dissemination***nodules diameter <10mm**liver**spleen**bone marrow**lungs***pulmonary miliary TB easily missed by chest X-ray**meninges

===baseline investigation=======blood====*full blood count**clues for TB - leukopenia, anemia, thrombocytopenia*liver enzyme, renal function, electrolyte**for baseline to monitor Tx side effect or to adjust dose*diabetes*co-infection**HIV**Hep B - HBsAg**Hep C - HCV-Ab====imaging====*chest X-ray*other targeted imaging ===microbiological=======smear/microscopy====*Ziehl-Neelsen of sputum**positive smear needs cavitation**children and HIV-positive tend not to cavitate**specificity 98%*fluorescent ====culture - 4-8weeks====*culture is definitive/reference standard*Lowenstein-Jensen medium*liquid medium 3 weeks ====PCR TB DNA====*Gene Xpert**Xpert MTB/RIF**can detect resistance to rifampicin ====histopathology====*tissue biopsy**caseating granuloma***multinucleated giant cells with nuclei arranged like a horseshoe ====urinary LAM antigen detection====*mycobacterial cell wall glycolipid antigen lipoarabinomannan (LAM)*marker of active TB*specificity 98%*sensitivity 40-70% ====Manteau text/tuberculin skin test (TST)====*low value for diagnosis ====Interferon gamma release assay (IGRA)====*T-SPOT/Quantiferon(QFT)*cannot distinguish between latent/active/used be treated ==Treatment==*needs prolonged Tx*needs multiple drugs ===1st line target===*cell wall synthesis**H - isoniazid (isoniotinic adid '''h'''ydrozide)**E - '''e'''thanbutol*DNA synthesis**R - '''r'''ifampicin*?**Z - pyra'''z'''inamide *2RHZE+4RH*2RHZE+4(RH)&#x2083; ===side effects===*hepatotoxicity - H, R, Z*ocular toxicity - E*peripheral neuropathy - H**add vitamin B6 (pyridoxin)*gout - Z*fever - Z*lupus - H*drug interaction related to CYP 450P - R**carbamazepine**oral contraceptive**methadone ===interrupted Tx===*interrupted during intensive phase**interrupted for > 14 days - re-Tx from the beggining**interrupted for < 14 days - continue*during continuing phase ===spinal/bone TB===*needs 9 months ===TB meningitis===*needs 12 months*2RHZE+10RH ===latent TB===*some options ==Management=====paradoxical reaction===*inflammation after commencing Tx*problematic in CNS, pericardial*co-Tx with steroids**CNS/meningitis,tuberculoma - dexamethasone**pericardial - predonisolone ===Directoly Observed Treatment, short course (DOTs)===*in high risk stuation*in homeless/chaotic social circumstance*in poor adherence/treatment failure *Dr. Karlos Stybro ===TB in pregnancy===*RHZE are safe*supplementation with VitB6 (pyridoxine) recommended**hyperemesis gravidarum ===TB in breastfeeding===*no contraindication*rule out TB in baby ===hepatotoxicity===*any GI complaint may represent hepatotoxicity*suspend all TB drugs until lab test revealed*risk**co-infection HIV, hepB/C**other chronic liver disease**alcohol**advanced age*early - 2-3wks, R,H; good prognosis*late - after 1mo, E; bad prognosis