What should I prescribe? Infection edition Flashcards

Question

Thrush (candidiasis - Candida albicans)

Answer 1

Cloprimazole Vulval/ vaginal itching, soreness and irritation Discharge is usually white and cheese-like, non-malodorous

Answer 2

Oral/intravag Metronidazole (2nd line: intravag Clindamycin) Loss of lactobacilli -> Bacterial overgrowth, not itchy but **fishy thin grey/white discharge**

Answer 3

??? Inflammation of the urethra with associated discharge (not caused by gonorrhoeae)

Answer 4

Penicillin Primary = painless ulcer Secondary (untreated primary after 4-10 weeks) = Widespread rash, multisystem, can become latent Tertiary (1-46 years after exposure) = neurological / CVS / gummatous 40% co-infected with HIV

Answer 5

Faecal microbiota transplant 90% success rate for c.diff diarrhoea compared to 30% with vancomycin Elevated **yellow plaques** join to form a pseudomembrane

Answer 6

**Self-limiting (2-3 days)** - supportive treatment e.g. fluids Gram -ve bacilli, aerobic N&V&D (mostly **non-bloody**), fever, abdo cramping Small intestine involved - **watery diarrhoea** Contaminated food/water, small infectious dose

Answer 7

Generally self-limiting but can last days to weeks **(longest lasting)** Supportive treatment with fluids Consider antibiotics if bloody diarrhoea Gram -ve bacilli, spiral/S shaped Fever, abdo cramping & profuse diarrhoea (can be **bloody**) Large intestine involvement Risk of HUS Mainly from eating contaminated poultry, faeco-oral route Longer incubation period of 1-7 days Haemolytic uraemic syndrome Triad of: anaemia, thrombocytopenia and AKI

Answer 8

Usually self-resolves within a **week** - supportive treatment Gram -ve bacilli **Bloody diarrhoea** with mucus and abdo cramping **Large intestine involvement** - colonic abcesses Risk of HUS Only needs small dose - spreads easily in families Spread from infected stools, person to person/ via flies Commonly affects **young children <5 y/o** Haemolytic uraemic syndrome Triad of: anaemia, thrombocytopenia and AKI

Answer 9

Antibiotics may be useful Gram -ve bacilli, produces enterotoxins -> hypersecretion of Cl- -> water follows into gut lumen **Watery diarrhea** Small intestine involved Faecal-oral route via contaminated water Common cause of travellers diarrhoea

Answer 10

Supportive, manage dehydration dsRNA virus Faecal-oral route - very small dose required Very common cause in under 5s - **adults rarely infected** (immunity lasts) Vomiting with high fever -> diarrhoea for up to a week Cl- secretion (created gradient -> increased Na into lumen -> water follows) SGLT1 disruption (reduced Na/glucose uptake, water moves into lumen via osmosis) Reduced brush border enzyme function (general malabsorption)

Answer 11

Oral rehydration therapy RNA virus Very common Adults and children - don't develop immunity as many strains Very small dose required - highly contagious and resistant to cleansing 1-2 day incubation period, 1-3 days of symptoms Vomiting, watery diarrhoea and fever Infects small intestine and damages microvilli (brush border enzymes disrupted) Anion secretion -> movement of water into gut lumen Vomiting due to delayed gastric emptying, vomit to relieve pressure

Answer 12

Normally self-limiting: Supportive treatment (fluids), may need anti-parasitics in at risk groups (AIDS) Non-motile protozoa parasite - Sporozoan Ingest oocyst via faecal-oral route but can also survive in bodies of water (infected by animal faeces) Risk factors are contact with animals, water and children Watery diarrhoea - malabsorption (brush border enzymes) - Cl- secretion

Answer 13

Antibiotics! and fluid rehydration therapy Motile protozoa parasite - Flagellate Mostly asymptomatic, symptoms more common in children Faecal-oral route with water supplies affected (developing countries) 10+ days incubation period Symptoms if present: diarrhoea and abdo cramping (can last up to 6 weeks) - damages proximal SI, villous atrophy Common cause of **persistent diarrhoea** Post-infection can cause **lactose intolerance**

Answer 14

Anti-protozoals/Metronidazole Motile protozoa parasite - Amoeba Higher prevalence in developing countries Excystation in colon -> invades mucosa Most cases asymptomatic but if symptomatic: bloody diarrhoea, inflammatory changes similar to IBD and (rarely) liver abscesses Faecal-oral route from contaminated food/water Can lead to severe colitis or toxic megacolon

Answer 15

Mild/moderate (<6 stools / 24hrs): hydration, antidiarrhoeal agents for symptom control Severe (>6): IV fluids and antibiotics if required Antibiotics only recommended for vulnerable patients and only shortens duration of symptoms Prevention most important - good hand hygiene, food and water precautions Diarrhoea most common symptom of travel related illness ETEC most common cause 3+ loose/watery stools +/- fever, abdo pain 14+ days duration - unlikely to be bacterial cause Risk factors: <6y/o, PPIs, blood group O (shigellosis, cholera), location (south/east Asia, central America, west/north Africa), dietary exposure

Answer 16

1st line - Artesunate 2nd line (if unavailable) - Quinine + doxycycline Vector - female Anopheles mosquito Incubation: 6 days - 4 weeks (most cases) Hx of fever, chills & sweats - cycle every 3-4 days Few signs except fever +/- splenomegaly Severe can affect CVS (tachycardia, hypotension, arrhythmias), resp (ARDS), GI (diarrhoea, deranged LFTs), AKI, confusion, cerebral malaria, thrombocytopenia, DIC etc. Investigations: - 3x Blood film - shows single-celled protozoa with headphone appearance - FBCs, U+Es, LFTs, glu, coag - Head CT if neuro signs, CXR

Answer 17

Supportive treatment only Vaccine available for children in endemic regions Virus Vector - Aedes aegypti mosquito Most 1st infection cases mild - asymptomatic to non-specific febrile illness 1-5 days duration Improves 3-4 days after rash (widespread, macular, papular rash) Reinfection with different serotype -> antibody dependent enhancement - Dengue haemorrhagic fever - Dengue shock syndrome (up to 30% mortality)

Answer 18

Chloroquine (not suitable for falciparum due to resistance) Give additional primaquine as can recur months-years later - dormant hypnozoites in liver Vector - female Anopheles mosquito Incubation (vivax/ovale): 6 days - up to 1 year+ Hx of fever, chills & sweats - cycle every 3-4 days Few signs except fever +/- splenomegaly Investigations: - 3x Blood film - shows single-celled protozoa with headphone appearance - FBCs, U+Es, LFTs, glu, coag - Head CT if neuro signs, CXR

Answer 19

1st line - IV Ceftriaxone (cephalosporin) 7-14 days 2nd line - Azithromycin (macrolide) Pakistan travel Hx - Meropenem Multi-drug resistant Fluoroquinolones e.g. ciprofloxacin may work Gram -ve bacillus, aerobic Systemic disease (bacteraemia/sepsis) 7-14 day incubation period Fever, headache, abdo pain, **no diarrhoea**, dry cough, relative bradycardia (would expect increased BP with fever) Complications: - intestinal haemorrhage & perforation - untreated = 10% mortality - chronic carrier state in 1-5% Paratyphoid is generally milder

Answer 20

IV benzylpenicillin and metronidazole (or in penicillin-allergic patients, clindamycin/clarithromycin monotherapy) NSAIDs and a single dose of corticosteroid recommended + aspiration Symptoms- severe throat pain, fever, bad breath, drooling, difficulty opening mouth, **hot potato voice, deviated uvula** May also show signs of sepsis - altered mental state, fever, tachypnoea, tachycardia and hypotension Can follow on from untreated / partially treated tonsillitis or on its own Aerobic or anaerobic bacteria Large abscess can cause Stertor (partial upper airway obstruction above the level of the larynx) - due to vibration of nasopharynx, oropharynx or soft palate - sounds like heavy snoring or gasping Complications: - deep neck space infection and potentially cause airway obstruction - Mediastinitis (tracks down deep neck to mediastinum) life-threatening

Answer 21

Treatment is usually conservative IV or oral antibiotics, intubation may be needed Rapid deterioration in children - don't examine child as may get distressed Usually secondary to bacterial infection e.g. Haemophillus influenzae Rare but more common in 2-6 y/os Symptoms: high fever, sore throat, dysphagia and drooling, **sniffing position** If airway compromised - stridor, raised RR, distress, hypoxia, +/- cyanosis

Answer 22

Common and usually not severe: self-resolves, managed at home Severe (stridor at rest, cyanosis etc.): overnight observation, O2, steroids Viral cause - mostly mild Infants 6m-3y/o have characteristic **barking cough**, worse with agitation, can -> stridor if crying

Answer 23

Usually self limiting - resolves in 2-3 weeks Supportive/symptomatic treatment = paracetamol for pain/fever, fluids, rest voice Inflammation and oedema of the larynx, often involving true vocal cords Usually viral and non-infectious Symptoms: hoarse/weak voice (swelling increases bulk of cords) and sore throat, Hx of URTI

Answer 24

Keep dry and treat with antibiotic ear drops "Swimmer's ear" Inflammation of external ear Symptoms: discomfort, pain, itch and discharge from external ear Rare complication: Malignant otitis externa

Answer 25

IV antibiotics - immediate admission Rare complication of otitis externa Very serious, potentially life-threatening, immunocompromised inc. diabetes at risk Becomes invasive and erodes through petrous part of temporal bone

Answer 26

Usually **viral** cause - **symptomatic treatment** e.g. paracetamol Bulging of TM is secondary to **bacterial cause** (Strep pneumoniae or Haemophilus influenzae) - build-up of pus/exudate within middle ear - increases pressure -> otalgia +/- fever, red TM - sudden relief when ruptures 1st line - **Amoxicillin** 5-7 days ear drops 2nd line - **Co-amoxiclav** ear drops If penicillin allergy - Clarithromyocin Complications: - Mastoiditis - Involvement of facial nerve (intrapetrous branches -> nerve to stapedius and chordae tamponae) - Intercranial complications e.g. meningitis, sigmoid sinus thrombosis, brain absess

Answer 27

Most resolve spontaneously in 2-3 months If persistent or impedes speech and language development - referral to ENT, may need grommets to maintain equilibrium "Glue ear" TM retracted and sometimes evidence of fluid (mucus - can see air bubbles) within middle ear

Answer 28

Urgent referral for IV antibiotics / surgery As middle ear cavity communicates via mastoid antrum with mastoid air cells Provides route for middle ear infections to spread into mastoid (temporal) bone

Answer 29

Surgery Chronic -ve pressure in middle ear (ET dysfunction) Pars flaccida (more vulnerable as less tense) forms pocket Stratified squamous epithelia and keratin trapped -> proliferate -> cholesteatoma Not malignant but slowly grows and expands - can lead to enzymatic bony destruction -> erode ossicles, mastoid/petrous bone, cochlea Painless, often smelly otorrhea +/- hearing loss

Answer 30

Usually self-limiting and resolves within 2 weeks - Supportive treatment e.g. fluids and rest Hx of URTI (viral) Involvement of all inner ear structures associated with hearing loss/tinnitus, vomiting and vertigo (very acute presentation)

Answer 31

Severe, initial symptoms usually last 2–3 days but usually recover gradually over a period of weeks through a process of central nervous system compensation Symptomatic treatment can be used acutely e.g. oral prochlorperazine Hx of URTI (viral) Usually no hearing disturbance or tinnitus - just vestibular Sudden onset vomiting and severe vertigo (lasting days) Thought to be due to inflammation of the vestibular nerve

Answer 32

Antibiotics 1-3 weeks following group A beta-haemolytic streptococcal infection (e.g. Strep pyogenes) normally from tonsils, pharynx or skin

Answer 33

Warm compresses +/- oral antibiotics Superficial infection of lash follicle gland with staphylococcus Red with white punctum Lump on outer part (margin) of eyelid

Answer 34

1/3 resolve spontaneously, may need surgical incision if persists Blocked duct of meibomian gland Painless, firm and palpable lump deeper within the lid which enlarges gradually Non-infective cause

Answer 35

Warm compress and lid hygiene Inflammation of eye-lid margin Crusting, dry eye-lids +/- swollen and red Causes: Staphylococcus infection, meibomian gland dysfunction

Answer 36

Broad-spectrum IV antibiotics Refer if unsure (e.g. can't open eye) Infection involving **superficial** tissues (anterior to septum) Secondary to superficial infections e.g. from bites, wounds Painful Ocular function (movements and vision) are unaffected

Answer 37

Broad spectrum IV antibiotics - urgently refer (opthalmology, ENT +/- neurosurgery) Infection involving tissues **within orbit** (posterior to septum) Spread of infection from paranasal air sinus (sinusitis) Proptosis/exopthalmous Reduced +/- painful eye movements Reduced visual acuity Risk of spread intercranially -> cavernous sinus thrombosis, meningitis Risk of permanent blindness

Answer 38

Self limiting but very contagious - good hygiene to avoid spread Typically viral cause (e.g. adeno-) Uncomfortable, gritty but not normally painful Watery +/- discharge