Other Medicine Flashcards
Most common cause of fever after travel to Sub-Saharan Africa and tropical areas
Malaria
Most common cause of fever after travel to Latin America or Asia
Dengue
Definition of severe malaria
Fever in last 48 hours
P falciparum infection, >100 parasites/200 leukocytes, no other causative organism
At least one of:
- Impaired consciousness, GCS <10
- Multiple grand mal seizures
- Jaundice
- Hypoglycaemia (<2.5)
- Hyperparasitaemia (parasite density >100000)
- Renal impairment
- Cardioresp distress
Causes of fever + haemorrhage
Viral haemorrhagic disease
- Dengue
Leptospirosis
Meningicoccaemia
Rickettsial infection
Investigation for malaria
Malaria antigen rapid diagnostic test (RDT)
Thick and thin blood films taken on 2 occasions
- >3 negative blood films on 3 consecutive days to rule out
Investigation for travellers diarrhoea
Only test stools if prolonged diarrhoea (10-14 days) or severe symptoms (fever, tenesmus, bloody stools)
- Stool culture
- Shiga toxin assay
- Ova and parasites
- Giardia and cryptosporidium antigen
Treatment of uncomplicated malaria
P. falciparum or unidentified species: artemether+lumefantrine (Riamet, Coartem) or atovaquone+proguanil (Malarone)
P. vivax, P. ovale, P. malariae, P. knowlesi: Chloroquine, hydroxychloroquine, artemethar+lumefantrine (Riamet, Coartem)
If P. vivax, P. ovale liver hypnozoites: Primaquine (do not give in G6PD deficiency-haemolysis)
Chloroquine resistant P. vivax: artemethar+lumefantrine + Primaquine
Management of traveller’s diarrhoea
Antiemetic
Oral fluid + electrolyte replacement
Loperamide for profuse diarrhoea
Empiric abx:
Ciprofloxacin 750-1000mg stat, or 500mg BD 3 days
Or azithromycin 1g stat or 500mg BD 3 days if South/SE Asia (high fluoroquinolone resistance)
Symptoms and incubation for traveller’s diarrhoea
Bacterial + viral - 6-48 hours incubation
- vomiting more prominent in Norovirus
- Rice water diarrhoea in cholera
Parasitic infection 1-2 week incubation
Slower onset, low grade symptoms
Malaria presentation
Plasmodium parasite
<1 month incubation
P. vivax hypnozoites can stay dormant for months-years
Fever, chills, sweats
Headache
Nausea, vomiting, anorexia
Body aches, general malaise
Fever, arthralgia/myalgia, rash
3 possible traveller’s infections:
Dengue
Zika
Chikungunya
Dengue presentation
Aedes aegypti mosquito
Incubation 4-10 days
Most asymptomatic or subclinical
Sudden onset fever
Arthralgia
Maculopapular or macular confluent rash 2-5 days after fever
Minor haemorrhage - epistaxis, heavy menstrual bleed, petechiae, gum bleeding
Extreme malaise
Headache behind eyes
Sore throat, conjunctival injection, abdo pain
Chikungungya presentation
Fever >39 several days-1 week
Bilateral, symmetrical arthralgia - small joints of hands and feet
Tenosynovitis
2-5 days after fever onset - maculopapular rash of trunk and extremities. Petechial or vesiculobullous in infants
Causes of travellers diarrhoea
Enterotoxic E coli (most common)
Enteroinvasive E coli
Enteroaggregative E coli
Shigella
Campylobacter
Salmonella
Norovirus (10-20%)
Protozoal parasites
Transmission of Hepatitis strains
Acute vs chronic
A, E - orofaecal, gastro symptoms, usually self-limiting
B, C, D - bloodbourne: intercourse, transfusion, vertical transmission, blood to blood
D always co-infected with B, indicator of worse prognosis. Cirrhosis, failure, ca.
C - 80% chronically infected
B - 50% chronically infected
Risk factors for
Hep A
Hep B, C, D
A - travel to high risk areas, sewage workers, MSM, IVDU
B, C, D - IVDU, tattoos, MSM.
B - endemic countries
HIV risk factors
Travellers and immigrants from Sub-Saharan Africa, SE Asia
MSM
IVDU
Related infections - Hep B, C, STI, TB
Symptoms of HIV
60% asymptomatic of acute infection
Fever
Malaise
Sore throat
Rash
Arthralgia/myalgia
Anorexia, weight loss, oral ulcers
Causes of meningitis
Viral - most common
Neisseria meningitidis
Strep pneumoniae
Haemophilus influenzae
Children:
Listeria monocytogenes
E coli
Enterococci
Herpes simplex
Consider partially treated meningitis, parameningeal focus (ears, sinus, cerebral abscess)
Management of suspected meningitis
Treat as bacterial until proven otherwise
Urgent medicine referral
IVabs if >20min delay to hospital
Neonates <3 months: Benzylpenicillin 50mg/kg, max 2g
Children 3 months to 10 years: Ceftriaxone 100mg/kg, max 2g
Adults: Ceftriaxone 2g + dexamethasone 10mg
IV access x2
IV bolus - 1L adult, 20mL/kg child
Bloods + blood cultures x2
Risk factors for meningitis
Infants, children, adolescents
Maori, Pacific
Exposure to smoke
Binge drinking
Other respiratory infection
Crowded house, institutionalism
Close contact with positive meningitis case
Immunocompromised
Cellulitis vs erysipelas
Cellulitis - Infection of dermis and subcutaneous tissue
Erysipelas - Infection of superficial dermis
Symptoms less likely to be cellulitis
Itch
Bilateral
Symptoms of nec fasc
Necrotising fasciitis
Symptoms
Management
Severe pain, systemic symptoms, purple discolouration, necrotic tissue, crepitus
IV ceftriaxone
Immediate referral
Risk factors for cellulitis
Elderly with poor circulation
Smoking
Immunocompromised
Diabetes
Overweight
Differential diagnoses for cellulitis
Thrombophlebitis
Lipodermatosclerosis
Radiation damage
Dermatitis
Fungal infection
Insect bite
Inflammatory breast ca
Antibiotics for cellulitis
Flucloxacillin
Children: 12.5-25mg QID 5 days
Adults: 500mg-1g tds/qid 5 days
Cefalexin
12.5-25mg/kg, 2-4 times/day, 5 days
500mg QID 5 days
Erythromycin
10-12.5mg/kg, QID 5 days
400mg QID 5 days
Co-trimoxazole
24mg/kg BD 5 days
960mg BD 5 days
Causes of UTI
E coli
Staph saporphyticus
Proteus
Klebsiella
Enterococcus
Diagnosis of catheter associated UTI
Fever >38
Suprapubic tenderness
Costovertebral angle tenderness
Urine dipstick or culture positive
No other cause of fever
Pyuria is common in catheter
Management of asymptomatic bacteriuria in pregnancy
Risk of preterm birth and low birth weight
Treat empirically, urine for culture
Treatment of UTI with haeamaturia
Macroscopic - treatment for 10 days, repeat urine 2 weeks post treatment
Microscopic - treatment for 7-10 days, repeat urine 1 week post treatment
Empiric antibiotic treatment for UTI
Men
Women
Pregnant
Child
Men:
Nitrofurantoin 100mg BD 7 days
Trimethoprim 300mg nocte 7 days
Cefalexin 500mg BD 7 days
Women:
Nitrofurantoin 100mg BD 5 days
Trimethoprim 300mg nocte 3 days
Cefalexin 500mg BD 3 days
Pregnancy:
Treat for 7 days
Not for trimethoprim first trimester
Not for nitrofurantoin after 36 weeks
Child:
Cotrimoxazole 24mg/kg BD 3 days
Cefalexin 12.5-25mg/kg BD 3 days
Augmentin 15m/kg tds 3 days
Nitrofurantoin - do not give in renal failure, CrCl <30
Symptoms of acute pyelonephritis
Fever
Flank pain
Nausea and vomiting
Augmentin
Co-trimoxazole
Cefalexin
Treatment of pyelonephritis
Cotrimoxazole 960mg BD 10 days
Augmentin 625mg tds 10 days
Cefalexin 1g tds/qid 10 days - only if susceptible and resistant to other choices
Refer pregnant women
Low threshold referral for elderly
Cause of Herpes zoster (shingles)
Varicella zoster virus
Recurrence in nerve root - stress, immunocompromisation, old age
Herpes zoster presentation
Blistering rash, allodynia, within dermatomal distribution, does not cross midline
Resolves in 10-15 days
Itching, tingling, pain along distribution and viral prodrome prior to appearance of rash
Treatment of Herpes zoster
Antiviral most useful within 72 hours of rash
Over 72 hours use if - new lesions, HZO, age >50, immunocompromised, prodrome presence, severe/disseminated rash, severe pain
Valaciclovir 1g tds 7 days
Aciclovir 800mg 5 times/day 7 days
Famiciclovir 500mg tds 7 days
Ice, calamine
Capsaicin cream (post herpetic neuralgia)
Lidocaine
Codeine
Tramadol
Oxycodone
Sometimes: prednisone, TCA, gabapentin
Complications of Herpes zoster
Uncommon in immunocompetent patients
Highest risk in lymphoproliferative cancers
Mortality 5-15%
Encephalitis
Meningitis
Pneumonitis
Blindness/permanent visual impairment - HZO
Post herpetic neuralgia
Causes of infectious mononucleosis
Epstein-Barr virus
Cytomegalovirus
Toxoplasmosis
HIV
Infectious mononucleosis symptoms and signs
Classic triad: Fever, pharyngitis, lymphadenopathy (posterior cervical)
Splenomegaly (50% in first 2 weeks)
Hepatomegaly + jaundice (uncommon)
Generalised maculopapular/urticarial/petechial rash - especially after amoxicillin
Fever + sore throat - 1 month
Fatigue - 2-3 months
Encephalitis diagnosis criteria
3 or more of:
Fever
Seizures
Focal neurological signs
CSF pleicytosis (WCC >5x10^6)
EEG slowing
Abnormal MRI
Causes of encephalitis
30-50% infective
Herpes simplex - most common
Measles
Varicella zoster
Adenovirus
Mumps
EBV
Enterovirus
Toxoplasmosis gondii
Mosquito, tick-borne virus
Mycoplasma pneumoniae
Influenza
Non-infective
acute demyelinating encephalomyelitis
antibody-mediated autoimmune disease
Paraneoplastic syndromes
Treat all suspected as infective until proven otherwise - antivirals + abx