Bacteria Flashcards
(47 cards)
What causes syphilus?
spirochete called treponema pallidum
How to syphilus transmitted?
transplacentally (mother to child) or sexually
Give the 3 stages of syphilus
primary, secondary and tertiary
What can congenital syphilus result in?
Miscarriage, stillbirth, congenital malformations
most common site for syphilus to occur? NB mcq
anogenital region
Primary syphilus: give the pathogenesis
- Ulcer known as chancre (painless and 3-90 days after exposure occurs)
- Heals within 3-8weeks and you get regional lymphadenopathy
- Treponema invade lymph nodes and spread via lymphatics
- Only see secondary syphilus once the organism is spread throughout the body.
- Chancre starts as small papule then gets bigger and uclerates
- ANOGENITAL region is most common NB MCQ!
- Oral cavity most common extra-genital site!
- The cancre looks like SSC so include that in differential!
Give pathogenesis of secondary syphilus:
-Disseminated disease!! systemic symptoms
-4-10weeks after primary syphilus (primary pyphilus needs to spread through the body first before secondary syphilus occurs)
-Resolves after 3-12weeks
-Not specific symptoms (malais, fever, fatigue) but very characteristic oral lesions coming up!)
-skin rash occurs
-30% oral mucosal mucous patches which fuse and create snailtrack lesions!
-Not ulcer though because ulcer involves full loss thickness epithelium.
-Conylomata lata (frequently anogenital). Do not confuse with conyloma acuminatum caused by HPV! prof van heerden likes to confuse you with this one!
NB test Q is explain or describe the oral manifestations f secondary pyphilus
What occurs in secondary syphilus in HIV patients?
- Chancre change is much bigger (lues maligna explosive and aggressive but is not malignant but looks like malignancy!) was a true and flase Q.
- Necrotic ulcers of face and scalp
IF you did not know the patient had syphilus and you see the condylomata lata, what does would you suspect in your differential?
Differential: 1) patient has HPV and on ARTS because of multiple squamous cell papillomas. 2) patient has hecks disease
3) syphilus (secondary)
Pathogenesis of tertiary syphilus:
- After secondary syphilus , latency of 1-30years. Free of lesions and symptoms.
- 30% of patients progress to tertiary.
- Tertiary stage of syphilus is life threatening.
- CVS and CNS involvement See characteristic lesions that are gummatous necrosis (gumma). Granulomatous inflammation occurs. Gummatous necrosis - syphilitic gumma (patient says his/her palate fell out).
- Syphilitic gumma causes midline palatal destruction, perforates into nasal cavity. NB test and exam question they looooove this part!.
- CVS (cardiovascular system): d2 endarteritis of blood vessels. Complications are: end arteries inflammed and occlude.
- Main 4 CVS issues are: 1. aortic aneurysms (weakening of wall of aorta), 2. left ventricular hypertrophy, 3. aortic valve insufficiency, 4. Congestive heart failure.
CNS problems with teriary syphilus are?
- tabes dorasalis (lose corrdination of movement)
- Generalised paralysis
- psyhosis and dementia
- paresis
- death
Give the additional features of tertiary syphilus:
- Ocular involvement
- foci of granulomatous inflammation- gummas
- palatal gummas perforate into nasal cavity (midline destruction of palatal destruction)
- atrophy and of tongue papillae = glossitis
- Nice question to ask final exam all the causes of midline palatal destruction= include gummas in tertiary syphilus.
Congenital syphilus give the 3 pathogonomic features (they love asking this shit)
Spirochaetes are around and in tooth germs as teeth develop!
1. hutchinsons teeth (hutchinsons incisors and mulberry molars)
2. oular interstitial keratitis (causes blindness)
3. Deafness (CN 8)
These 3 are also known as hutchinsons triad! NB NB
They give you a picture of hutchinsons incisors and ask what are other features you will find
In addition to hutchinsons triad what other features will you find in these patients with congenital syphilus?
Saddle nose deformity, high arched palate, frontal blossing, hydrocephalus, intellectual disability, gummas, neurosyphilus.
You are given a picture of hutchinsons incisors and asked to describe this picture features and other features that will likely be found. Describe (i know there is no picture but you should be able to give a desciption of this)
- Hutchinson incisors show their greatest mesiodistal width in middle third of the crown. The incisal third tapers to incisal edge. This results in resembling a straight edge screwdriver. Incisal edge exhibits a central hypoplastic notch that looks U shaped inwards towards the cervical area.
- mulberry molars taper towards the occlusal surface with a constricted grinding surface. The occlusal anatomy is abnormal with numerous disorganised globular projections. resembling a mulbery molar on the surface
Give 3 special investigations to diagnose syphilus
- Active lesions (like chancre or mucous patch) take a smear and do darkfield microscopy which highlights the spirochetes.
- iF found positive then want to see if treponema pallidum- do IMF (immunofluorescent) antibody test on the smears
- serology
- also do warthin starry stain for syphilus
Management and prognosis of syphilus:
Penecillin (dosage varies with stage, CNS involvement and immune status)
Use doxycycline if pt is allergic (also tetracycline(NEVER TETRACYCLINE TO CHILD)- TOOTH STAINING), erythromycin, ceftriaxone)
What is the main organism that causes TB?
Mycobacterium tuberculosis
How do we distinguish between infection and active disease of TB?
TB skin test used! they inject it into skin and if you exposed to it your body will have antibodies against it and your cells will respond to antigen.
Explain primary TB
-previously exposed
-spread by resp droplets to lungs
If immune system is down then will get TB because bacteria are then freed basically.
In healthy patients granulomatous inflammation surrounds the TB bacilli. Then you asymptomatic. Bacilli remain dormant. Intact immune system prevents disease (as long as you have competent immune system you should not get reactiviation.)
Secondary TB explain
If you are immunocompromised in ANY way then these organisms will lead to what we call 2ndary TB.
Immunocompromised is eg: child with HIV exposed to TB for first time.
The dormant bacilli reactivate when immunocompromised but most o time occurs when patient is re-exposed to TB when their immunity is down
-5 to 10% occurs later in lie. d2 immunosupression, immune system prevents replication of dormant bacilli.
Give 3 predisposing factors of TB
- HIV/AIDS
- old age
- diabetes
- immunisupressed medication (cyclosporine due to organ transplant or cortisone)
- social factors (poverty and crowding)
Give the consequences of TB infection NB will be asked- If a patient has active TB what could be the consequences of infection?
- Bronchial erosion- cough up sputum (filled with bacilli). They then re-infect themselves at other sites oral lesions. Can also get GIT lesions (when swallow sputum). Also how you get TB ulcer on the tongue.
- Pulmonary artery erosion (if the lesion erodes into the pulmonary artery)- infective material circulates back into lung so pt refinecting self. then get widespread lung involvement!!!
- pulmonary vein erosion: if the lesion erodes into the pulponary vein to left side of heart to haematogenous spread via aorta- called military TB
- lymphatics erosion (if the lesion erodes into a lymphatic) -lymph node and spleen involvement/ enters thoracic duct goes to heart and bloodstream
- Death
explain what a scrofula is
Its a oropharyngeal TB with lymph node involvement. If you get TB in cervical lymph nodes then it erodes onto the skin its caled scrofuladerma
