STIs, stings, malnutrition, altitude Flashcards
2 key issues with altitude mountain sickness
High altitude pulmonary oedema (HAPE)
High altitude cerebral oedema (HACE)
Score system for AMS
Lake Louise score
3–5 = mild, 6–9 = moderate, and 10–12 = severe
Define HACE
High-altitude cerebral oedema
AMS
+ Altered mental status OR ataxia
Prevent HACE. Name 2 things
Acetazolamide [dex works too]
Ascend slowly
Minimal physical activity
Hydration
Name 3 things that affect validity
- Selection bias
- Information bias
- Confounding
What is PPV? What does it depend on?
The probability that a person with a positive test truly has the disease
Depends on sensitivity but also on
* the prevalence of the disease in the population tested OR
* in the pre test probability in the individual tested
How can you summarize test performance by combining sensitivity and specificity
Likelihood ratio
How many times more a positive (or negative) test is likely to occur in a diseased (or non diseased) person
* LHR + = Se / (1-Sp)
* LHR - = (1-Se) / Sp
Gene Xpert has Sensitivity 95%, specificity: 99% what is the likelihood ratio of an infected person?
LHR + = 0.95 / (1-0.99)
= 95
A positive test is 95 times more likely to occur in a person with TB
Tropical sprue biopsy? rx?
Partial vilous atrophy
increased villous crypts and mononuclear cellular infiltrates, enlarged epithelial cells,
Prolonged erythromycin + folic acid
Which vaccines for respiratory global priorities for kids
Pneumococcal
H influenza
Malnourished children with eye disease need what? Key diseases this is ++ relevant in
Vitamin A
Measles / diarrhoea
Guinea worm infection called? Seen on ulcer? Dx?
- Dracunculus medinensis
- Pearly uterus seen poking out
- Identify worm/larvae after exposure to water
Most common cause of anaemia worldwide
Hookworm
Key drug causing macrocytosis
Hydroxycarbamide
Why testing for STIs important for HIV
facilitates transmission of HIV - much more likely if eg ulcerated skin
Hb make up in sickle cell? carrier?
95% HbS, 5% HbF
30%HbS, 70%HbA
Sickle cell parts of chronic Rx
Folic acid
Penicillin prophylaxis
hydroxycarbamide to increase HbF
B thalassaemia blood film
Hypochromic microcytic anaemia
[would expect to have raised MCV due to anaemia but the low MCV is due to ineffective erythropoesis]
G6PD inheritance ? key drugs causing reactions?
X linked
PANDS
Primaquine, Aspirin (acetylsalicylic acid), nitrofurantoin, dapsone, sulfonamides
screening test for G6PD in poor places?
Methemoglobin reduction test
[enzyme assays / genetic analysis if rich]
what does it mean if RBCs are hypochromic eg in iron deficiency
> 50% of cell is pale in colour on blood film
blood film b12 / folate deficiency
Macrocytic anaemia with hypersegmented neutrophils
Most common issue following viper venom? Cheap test?
Lack of clotting
WBCT20 (whole blood clotting test 20)
take 20ml blood and put in clean tube
-Leave it undisturbed for 20min and see if it can still be poured
-If still liquid = hypofibrinogenaemia
When antivenom in snake bites
swelling >50% affected limb or clinically unwell
Scorpion sting key cause of morbitiy ? rx?
Autonomic nervous system
-Hypertension
-CV failire
-Pulm oedema
Antivenom
Prazosin for HTN / cardiac failure
Diruetics / vasodilators for pulm oedema
The characteristic sign of severe envenoming from widow spider? real name?
HTN (similar to scorpion)
[abdo pain, autonomic, pain at bite]
Latrodectus
Bite which pain develops over hours, initially white ischemic area which breaks down into a eschlar over a week = ?
Loxosceles ssp
(Recluse spider bite)
Bite -> priapism, HTN, sweating tachy?
Banana (brazilian wandering) spider
-Phoneutria
Only in South America
Trick for Rx of venomous fish sting?
Immerse in hot water
-the venom usually heat labile
Key issue with any antivenom?
Anaphylaxis common
2 diabetic syndromes more or less only seen in tropics:
present young and hyperglycaemic with pancreatic fibrosis/calcification?
West African young with DKA which remits after acute Rx? Assoc with?
HIV?
Malnutrition-related diabetes
DKA that resolved - Atypical ketosis prone type 2 diabetes
HHV8
ART- related diabetes
Key issues for diabetic management in rural places
Late presentations
Irregular food supply / western diet adopted
Cultural benefit of being overweight / obese
Lack of insulin / drugs
Lack of dietcians / podiatrists
Poor health education
Lack of labs / monitoring equipment
which 2 infections should you screen for before giving someone with asthma a course of pred in the tropics?
Entamoeba histolytica - amoebic dysentery
Stronglioglaisis - hyperinfection syndrome
Name 3 causes of epilepsy in developing countries
Hypoxia at birth
head injury
Previous cerbral malaria
HIV + secondary infections eg cryptococcus / toxoplasmosis
Hydatid cytsts
Neurocystercosis (T Solium)
Common antiepileptic available in resource poor places
Phenobarbital
start at 30mg daily and increase up to 90mg
What is often used as an indicator of the severity of a humanitarian emergency?
Crude mortality rate Eg >1/10,000/day
or under 5 mortality rate
MSF 10 parts of emergency response?
1 - initial assessment
2 - measles immunisation
3 - water and sanitation
4 - Food and nutrition
5 - Shelter and infrastructure
6 - Health care in the emergency phase
7 - control of communicable disease epidemics (Eg cholera, shigella, malaria, other respiratory )
8 - Public health surveillance
9 - human resources and training
10 - Coordination
Initial assessment of humanitarian emergency aspects
- Geopolitical context
-Demographics of the population
-Map of the site with characteristics of the environment - Food/water / shelter availability
- major health/diseases
- Human / materials required
- Which local / national organisations can help
Which easy vaccine should be distributed in a humanitarian emergency? +supplement?
Measles + vit A (and zinc)
Minimum water required in a humanitarian emergency? How to test / clean?
5L/person/day
ideally 20L to minimise risk of water bourne illness
Test for coliforms with test kit eg del agua / oxfam kit
chlorination
Latrine requirements in humanitarian emergency
minimum 1/100 persons initially -> aiming for 1/20 or one per household
in humanitarian emergency which disease needs to be often neglected until health system better established
TB
What percentage of <5 deaths are related to malnutrition
50% of the 10M deaths a year
Moderate vs severe malnutrition definitions? weight-for-height Z score? height for age? Extra?
Moderate
Weight for height - 2-3 SD below normal (70-79%)
MUAC <12.5cm
Severe
Weight for height - >3 SD below normal (<70%)
MUAC < 11.5cm
[Weight for age (<60%)
Height for age - >3 SD below normal (<85%)
Presence of symmetrical oedema (kwashiorkor)]
Symmetrical oedema due to malnutrition is called
kwashiorkor
Oedematous malnutrition key features
Hair which is easily pluckable
Eye changes from vit A defieicny
Anaemia - Mixed deficiency
Mental - apathy and irritable -> coma
Liver - enlarged and fatty
Anorexia
Skin - hyperpigmented and dry / flaky
Enlarged fatty liver
Ascities is rare
Oedematous malnutrition key features
Hair which is easily pluckable
Eye changes from vit A defieicny
Anaemia - Mixed deficiency
Mental - apathy and irritable -> coma
Liver - enlarged and fatty
Anorexia
Skin - hyperpigmented and dry / flaky
Ascities is rare
Electrolytes malnourishment
Hypo Ca/K/Mg
HypoNa in blood but raised total body Na
Initial stabilisation of malnourshment rx?
Prevent:
-Hypoglycaemia - frequent small feeds
-Hypothermia - keep warm
-Treat dehydration and shock - ReSoMal (rehydration solution for the malnorished) - type of ORS
-Correct electrolytes
-Rx infection
-Mutrients - all should get folic acid / zinc / copper / vit A
[Should always aim to keep fluids ORAL as high risk of fluid overload / cardiac failure]
Which feed is often used in acute severe malnutrition
F75 used for first 2-7 days
- Has less protein/calories/fat as not intended for weight gain
- Avoids refeeding syndrome
F100 - used for rehab phase
Unconcious shocked malnourished child rx
5mg/kg 10% IV dextrose
Warm
15mg/kg over 1 hr [Eg Darrows with 5% glucose]
what is malnutrition wasting called
Marasmus
Vit A found in? initial Sx? seen on exam in deficiency? what happens eventually? Retinol?
Green leafy veg
Dry / gritty eyes with worsened night vision
On exam - Bitot’s spots (grey or white plaques on lateral aspect of conjunctiva)
Keratomalacia eventually - whole eye breaks down -> irreversible blindness
Retinol often normal even in deficiency - only reduces once very severe
What is gritty eyes from vit A deficiency termed?
Xerophthalmia
Vit B1 called? syndrome when deficient?
Thiamine
beriberi
[Also causes wernicke-korsakoff]
Beriberi (thiamine b1) deficiency 2 forms?
Wet - cardiomyopathy -> peripheral oedema
Dry - painful polyneuropathy
Diagnosis of b1 deficiency can use what test?
red blood cell transketolase enzyme reduction
B3 is called? Syndrome when deficient?
Niacin / nicotinic acid
Pellagra
-Diarrhoea
-Dermatitis
-Dementia
Key rash in pellagra?
Hyperpigmented affecting neck
‘cascals necklace’
Which deficiency -> gingivitis? Leads to?
Vit C (ascorbic acid)
Bleeding - from gums and base of hair follicles
Main risk factors for diarrhoea name 3
Malnutrition
Low birth weight
Lack of breastfeeding
No measles vaccination
Crowding
Indoor pollution eg open fires
Which cells kill virus-infected cells in innate immune response
NK cells
CD-8 cells
Which IL key for TB
IL-12
Why HTLV-1 leads to bad stronglyoglotides
Blocks IL-5 which would usually stimulate eosinophil production
Which Ig looks like a pretty snowflake (looks like 5 groups of normal ig_
IgM
Which Ig on mucosal surfaces
IgA
Which Ig is not secreted and remains as a cell receptor
IgD
Define MDR TB
Resistant to Rifampicin and Isoniazid
how much of daily energy should come from protein? fat?
Protein - 10%
Fat - 20%
Name a screening tool for malnutrition
- Nutritional Risk Screening 2002
- Malnutrition Universal Screening Tool
- Mini‐Nutritional Assessment – Short Form
Moderate/severe malnutrition.
Weight loss?
BMI?
Normal vaginal pH? Why is it this?
<4.7
Lactic acid production by Lactobacillus
(L. crispatus and L. jensenii)
Which vaginitis is discharge yellow/green? white? odours? strawberry cervix? ‘clue cells’? Usual pH for 3 key conditions?
Which bacteria are commonly implicated in BV? Rx?
Loss of lactobacilli -> growth of commensal
Gardnerella vaginalis
[Vaginal Garden]
Metronidazole or tinidazole or clinda
homogeneous, grey-white discharge , uniformly adherent to vaginal epithelium? Name a score system for Dx? Rx if preg?
BV
Amsel criteria = 3 of:
– homogeneous discharge
– pH >4.5
– clue cells (>20%)
– amine odor on addition of KOH (+whiff test)
Nugent score (gram stain findings)
Intravaginal Metronidazole or clinda
Trichomonas vaginalis rx?
Metronidazole / tinidazole
Which candida in thrush? Rx? If Preg?
C. albicans
Flucondazole
Preg - vaginal clotrimazole
Diptheria rx
Antitoxin + penicillin/erythromycin
Calais Camp and see refugee patient who presents with a rash. It started in his groin 3 weeks ago and has since spread. It is pruritic and keeps him up at night. He came now as he has an open wound in his inner right thigh that is painful with some purulent discharge.
Scabies
Ivermectin / permethin cream
- Cambodian refugee 20 yrs prior
- Presents with acute LLQ pain Intermittent loose stool, perianal pruritis
- PMHx- SLE with ESRD on dialysis
Strongy hyperinfection
Syphilis, herpes, chancroid, LGV, donovanosis.
Organism?
Number of lesions? appearance?
Characteristics?
Lymphadenopathy?
=? rx?
Herpes simplex (probable HSV2)
Acyclovir - no cure
Painful and has lymphadenopathy? rx?
Chancroid (haemophilus ducreyi) - painful / purulent
ceftriaxone
[Cipro/azithro options]
=? rx?
Syphilis (Treponema pallidum)- often painless and clean
benzylpenicillin
=? rx?
LGV - chlamydia trachomatis (often rapid healing of ulcer then affects lymph nodes)
Doxy
=? rx?
Granuloma inguinale (klebsiella granulomatis) - especially if ‘beefy’ red lesions
Azithro / doxy
Genital disease with vesicles =
Herpes
How to diagnose herpes? aciclovir resistant?
PCR - Sensitive and specific
Viral culture - not sensitive
-Only way to determine aciclovir resistance
Name 3 herpes prevention strategies
Avoid sex with lesions
Condoms
Suppressive antiviral therapy
Disclosure of serostatus
HSV 1 vs 2 locations
1 - oral and genital
2 - only genital
Prodrome then Firm, deep-seated, well-circumscribed, sometimes umbilicated lesions
– Starts on face and spreads to extremities, including palms & soles
Mpox
Name 3 Ddx of disseminated rash
Hairless Sexy Men Get Very Fucking Hard Muscles
HIV
Syphilis
Mpox / Other pox viruses
Gonococcal (Disseminated ) infection - especially if pustulating
Varicella/VZV
Herpes (Disseminated )
Fungal infections (disseminated)
Molluscum contagiosum
Name 2 causes of proctitis
Gonorrhea
Chlamydia (including LGV)
HSV
Groove sign - LGV
Rx?
Donovanosis (Granuloma Inguinale) (bright red beefy)
Klebsiella granulomatis
Azithro
Infectious cause of stroke in a young person
Neurosyphilis
(Cryptococcus + HIV rare)
Partner is known to have syphilis what should you do
Treat empirically - Benpen
On TB/HIV rx present with shortness of breath, irritable (per cousin), minor muscle wasting with possible wt. loss. Diarrhoea and this rash in sun-exposed areas
=?
Key drug implicated?
Niacin deficiency (B3) - pellegra
Diarrhoea, dementia, dermatitis
(often round neck)
Isoniazid - interferes with niacin metabolism
“Walking in water”, swollen feet - which vitamin deficiency most likely
B1 - thiamine (wet beri beri)
Isoniazid leads to which vitamin deficiency?
B3 (naicin) -> pellegra
10F Gradual weight loss, fatigue, brought in because “everything hurts
Physical exam: normal height/weight for age
* Mouth ulcers
* Spots in eye
Vit A deficiency
Arrested growth
* Vitamin A deficiency symptoms
* Altered taste
* Impaired immunity
* Hair loss, poor skin integrity
=which deficiency?
Zinc deficiency
18M taking TDF/FTC for PrEP presents to urgent care with a rash 0 diffuse, non pruritic, non painful and made up of erythematous macules on his chest, back, palms, and soles
Labs with normal BMP, CBC, but elevated
AST (350) and ALT (450)
–4 th generation HIV and Monospot negative
Dx most likely? Ix?
Syphilis
o Rapid plasma reagin (RPR)
o Treponemal antibody:
Which stages of syphilis might you get neurosyphilis
Syphilis Rx, Primary / secondary / latent / neuro?
Primary / secondary / early latent
-Ben pen single dose [half of dose into each butt cheek]
Late latent / unknown latent
-IM ben pen for 3 weeks
Neuro
-IV Benpen
Non gonococcal urethritis in men top 3 causes
Chlamydia trachomatis (15-40%)
Mycoplasma. genitalium (15-25%)
Trichomonas vaginalis (1-8%)
Most common presentation vit A toxicity
Headache
WHO guideline for Abx in acute severe malnutrition
Amox empiric treatment
Mycoplasma genitalium rx
Doxycycline
followed by Moxifloxacin
Specific serovar of Lymphogranuloma venereum
Caused by L1-L3 serovars of C. trachomatis
16F No PMH
facial rash for past 2 months, which started on her arm and spread to her axilla, chest and face
On biopsy (Warthin Starry silver stain)
Treponema pallidum
2 key predictors of neonatal mortality
Low birth weight
Preterm
[IgG mostly passed from mother through placenta towards end of pregnancy]
Neonatal sepsis top bugs ? How do these change depending on income ?
Gram-positive
-Coag-negative staph (neonates = essential immunocompromised)
-S aureus
-Group B strep
Gram Negative - Higher risk of death
-Klebsiella
-E coli
-Pseudomonas
Resource-rich = gram positive
Resource-poor = gram negative
Main causes of neonatal pneumonia
Gram positives - GBS and S. aureus
Top 2 causes neonatal meningitis
GBS
E. col
Vag and anus
[2/3rds of cases between them]
Rx first line neonatal sepsis? What Ix should be done on all neonates with unknown sepsis
Ampicillin + gentamicin
LP
Key protein in breast milk that is very protective
lactoferrin
Scorpion sting local effects usually?
immediate agonising local pain with minimal swelling
[Exception - Hemiscorpius lepturus (Iran, Iraq, Pakistan)
* painless sting, followed by swelling blistering, necrosis]
What are the systemic effects of scorpion stings
Ion channel toxins
1 - Autonomic storm [ think pheochromocytoma]
-Parasympathetic (cholinergic) - vomiting, sweating, hypersecretion, pancreatitis, priapism
-Sympathetic (adrenergic) - “goose bumps/flesh”, tachycardia, cardiovascular, myocarditis pulmonary oedema, hyperglycaemia
2-Neurotoxic effects:
fasciculations, tonic-clonic spasms “pseudo-convulsions”,
nystagmus, opsoclonus, irritability, paralysis, ptosis
Rx scorpion skin local?
Local anaesthetic - eg ring block of the affected finger
Scorpion sting systemic Rx?
Keep calm
Antivenom
ICU - may need dobutamine for LVF
-Prazosin for HTN
Sx?
Widdow - lactrodectus
Profuse sweating
-> Muscle Eg Abdomonal rigidity
What happens when I bite you?
Key complication?
‘Recluse’ loxosceles - Necrotic araneism (arachnidism)
Initially painless
- Develop slow burning / stinging etc
->12-72hrs ‘red white and blue sign’
-+ systemic symptoms eg headache, fever, scarlet rash
(see below)
After 3-7 days black necrotic eschar
Key comp = Haemolytic syndrome
-> fever, jaundice, haemoglobinuria with AKI
-> respiratory distress
Local sx? Systemic?
Latin American wandering/armed/banana spiders (Phoneutria
Local sx of goosebumps/sweating
-note wide bite marks
Hypertension -> stroke
Priaprism
[rapidly-evolving headache, nausea, vomiting]
Key issue when kept as pets
Tarantula
Fire hairs -> local issues
Bite is mostly just trauma related
-> mild local swelling / muscle spasms
what happens if you touch me?
rx?
possibly fatal bleeding and kidney failure
Rx - Antivenom
Which scorpions cause Cardiorespiratory effects
Eg hypertension, shock, tachy- and brady- arrhythmias, ECG
changes, pulmonary oedema
Leiurus, Androctonus, Hottentotta, Tityus
[Left atrial heart tachy]
Which scoprions cause neurotoxic effects?
erratic eye movements, fasciculation, muscle spasms (pseudo-convulsions) causing respiratory distress
Centruroides, Parabuthus
[Cerebral Paralysis]
Box jellyfish sting
Chironex fleckeri
