Infectious diseases Flashcards
What is a septic screen?
- FBC including WCC
- Blood culture
- Acute phase proteins e.g CRP
- U+Es
- Urine sample
- LFTs
- Gas including lactate
- Consider:
- CXR
- LP
- Rapid antigen screen on blood, CSF, Urine
- Meningiococcal and pneumocccal PCR on Blood/CSF
- PCR for viruses in CSF
What are the red flags for a septic child?
- Fever >38 if under 3 months and fever >39 if 3-6 months
- Colour- pale, mottled, blue
- Level of consciousness reduced, focal neurological signs, neck stiffness, bulging fontanelle, status epilepticus, seizures
- significant respiratory distress
- Bile stained vomit
- severe dehydration or shock
What are the causes of meningitis in
- Neonates-3 months
- 1-6 months
- > 6 months
- Neonates-3 months
- GBS
- E.Coli
- Listeria monocytogenes - 1-6 months
- Neisseria meningitides (gram -ve diplococci)
- strep pneumoniae
- H influenza - > 6 months
- Neisseria meningitides
- Step pneumoniae
- h. influenza
What is the pathophysiology of meningitis?
Bactaraemia - released into blood
cerebral oedema - raised ICP - reduced cerebral blood flow
Vasculopathy leading to hydrocephalus
What is the presentation of meningitis?
symptoms (6)
signs (6)
Fever headache photophobia lethargy poor feeding drowsiness
Signs
- fever
- purpuric rash
- neck stiffness
- bulging fontanelle
- brudzinki/kergnigs sign
- focal neuro
- altered consciousness
- opisthotonus
What investigations for meningitis?
1. LP 2 Blood cultures + PCR 3. blood glucose 4. rapid antigen screen on urine 5. throat swabs * do not delay, start tx
When is LP contraindicated in meningitis?
signs of raised ICP
- focal neuro signs
- papillioedema
- bulging fontanelle
- DIC
- signs of cerebral herniation
What is the management of meningitis?
- Abx - cefotaxime, ceftriaxone (IV)
- cefotaxime + amoxicillin if under 3 months - steroid - dexamethsasone to reduce frequency and severity of hearing loss + neuro damage
- Fluids
- cerebral mointoring - mechanical ventilation if resp distress
- public health notification + CIPRFLOXACIN for contacts
What is the proohylaxis for meningitis?
- meningiococcal and h.influenza
- Group C meningioccal
- Ciprofloxacin
2. Group C - give MEN C vaccine
What are viral causes of meningitis?
2/3rd
enterovirus, ebv, adenovirus, mumps
What is impetigo and how does it present
What is the cause?
highly contagious skin infection
presents as golden crusted skin lesions, usually around mouth but also face, neck and hands
- can be primary infection
- or it can be secondary to atopic eczma, scabies or insect bites
what are the causative agents? (impetigo)
How does it spread?
- staph aureus and strep pyogenes
- spread by contact with discharge
What is the tx for impetigo?
school?
- topical fusidic acid
- topica mupirocin
- flucloxacillin for extensive infections
exclude from school until crusted or 48hr after starting abx
What is Kawasaki?
What is the main risk for Kawasaki?
Kawasaki is a rare systemic vasculitis
Can lead to coronary artery aneurysm***
MI, myocarditis, pericarditis
What is the presentation of Kawasaki?
- high fever that is ongoing for >5 days, not broken by antipyretics
- conjunctivitis
- bright red cracked lips
- strawberry tongue
- cervical lymphadenopathy
- red, swollen, peeling palms and feet
What is the management for Kawasaki?
- high dose aspirin
- Intravenous immunoglobulins
- Echo to detect coronary artery aneurysm
What is the presentation of measles?
- fever, coryzal, cough, conjunctivitis
- kopliks spot (white spots) on buccal mucosa
- widespread maculopapular rash, beginning behind ears
What are possible complications of measles?
- otitis media
- pneumonia
- encephalitis
What is the management of measles?
- suppotive
- isolate
- immunocompromised - antirectroval
- vitamin A in low income countries
When is measles infectious
what is the incubation period?
prodrome to 4 days post rash
icubation = 10-14 days
How does rubella present?
- low grade fever
- pink maculopapular rash, spreading from face. gone by day 3-5
- lymphadenopathy (suboccipital and pericauricular)
What are complications of rubella?
- arthritis
- encephalitis
- thrombocytopenia
What is the incubation period for rubella?
14-21 days
What is slapped cheek syndrome caused by?
- slapped cheek (erythema infectiosum) caused by parvovirus B19
What is the presentation of parvovirus?
- fever
- malaise
- rash on face,
- spreads to maculopapular rash on trunk and limb
What can parvovirus lead to?
aplastic crisis (when not enough new RBCs made) e.g in sickle cell disease
what does parvovirus fetal disease lead to?
-fetal hydrops, death due to anaemia
What type of bacterium causes diphtheria?
Gram +ve
What does diphtheria bacterium cause?
Exotoxin causes local necrosis and pseudomembrane in nose, tonsils and or pharynx
rash
cervical lymphadenopathy
heart block (necrosis of heart, neural and renal tissue)
How do you manage diphtheria?
penicillin
antitoxin
What is a risk factor for diphtheria?
recent travel to eastern europe, asia
Which virus causes Mumps?
paramyxovirus
What is the presentation of Mumps?
- fever
- malaise
- parotitis (first unilateral then bi)) may get earchache or pain on eating
How is mumps transmitted?
via droplets
What investigation result may be raised in mumps?
Amylase
Whats the complication of mumps
pancreatitis
epididymo-orchitis
menongioencephalitis
What is the management of mumps
- rest
- paracetamol
- notifiable disease
When is someone with mumps infectious
When is the incubation stage?
- 7 days before and 9 days after parotid gland swlling
2. incubation = 14-21 days (same as rubella)
What causes scalded skin syndrome
- mainly staphylococcus auerus, can be epidermidis in neonates and ITU
How does staphylococcal skin infection present?
- fever
- extremely tender red peeling skin at flexures e.g -neck, axilla, groin
Nikolsky’s sign - separation of skin on gentle pressure
- can be prodrome of conjunctivis and sore throat
What causes Skin peeling in staohylococcal scalded skin syndrome
- staph releases endotoxins between layers of skin - proteins are proteases break down proteins holding skin tohetjer
What is the management of SSSS? (7)
1st line Abx = flucloxacillin IV Fluids and electrolytes topical therapy - fusidic acid/mupirocin analgesia emolliant physio due to affecting limb flexures
What pathogens cause hand foot and mouth disease?
- Cosackie 16
2. Enterovirus 17
What is the presentation of hand foot and mouth?
- start with mild symptoms of sore throat, fever, oral ulcers
- Painful vesicles on hands, feet, mouth (oral ulcers) and buttocks
How contagious is hand foot and mouth?
Very contagious
What is the management of hand foot and mouth ? School?
- supportive - hydration and analgesia
2. dont need to be excluded from school but should stay home until feeling better
What causes Scarlet fever?
Reaction to erythrogenic toxin released by Group A haemolytic streptococci
How does scarlet fever present?
- Fever - lasting 24-48hrs
- Malaise, headache, N+V
- sore throat
- strawberry tongue
- Rash: fine punctuate erythema, starting in torso, sparing face and palms/soles, can have sandpaper texture, pallor around mouth
What is the incubation period for scarlet fever?
How do does scarlet fever spread?
2-4 days
spreads via resp droplets or direct contact with nose/throat discharge
What is the investigation for scarlet fever?
throat swab
start Abx immediately
What is the management? (3)
- Oral Penicillin V for 10 days (Azithromycin for allergic)
- Can go back to school 24 hrs after starting Abx
- Notifiable disease
Describe scarlet fever rash
complications?
fine punctuate erythema (pinhead) starting in torso and sparing face, palms and soles. Can have a sandpaper texture, pallor around mouth
- otitis media
- rheumatic fever
- glomerulonephritis
What virus causes chickenpox?
Varicella zoster virus
How is chicken pox transferred?
spread via respiratory route
can be caught from someone with shingles
When is someone with chickenpox infectious, what is the incubation period?
4 days before rash 5 days after
incubation period is 10-21 days
What is the presentation of chickenpox
- fever, systemic upset
- papules -> vesicles –> pustules –> crust
What is the management for chicken pox in normal situation?
keep cool, trim nails
calamine lotion
school exclusion until crusted
What is the management of chickenpox in immunocompromised and Neonate exposed peripartum? What should you give if Chickenpox develops?
What should you not use?
Varicella zoster immunloglobulins
IV acyclovir
Do not use NSAIDs - increased risk of secondary bacterial infections
How does septicaemia present? (4)
Red/purple non-blanching rash.
Cold hands and feet.
Tachypnoea.
Flu like symptoms
How does immune deficiency present?
severe disease presents in neonates/infants and ummunological emergency
- Failure to thrive
- Skin problems
- chronic chest problems
- organomeglady
- lymphadenopathy
What is the normal infant lymphocyte count?
> 2.5
What is a type of immune deficiency?
Severe combined immune deficiency (SCID)
When should you investigate immune deficiency? (3)
- frequent or unsually severe infection
- infection with unsual organism
- family hx
What investigations should you do for immune deficiency?
- FBC - low total WBC, neutrophils and lymphocytes
- Total Ig G,A,M +/-E
- responses to routine immunisations
- lymphocyte subsets - number of T and B
- Lymphocyte function
What is the management of immune deficiency?
- Antiobiotic/antiviral promptly
- replacement immunoglobulins
- bone marrow transplant
Which immunglobulins do new born infants
- make themselves
- make some of
- most from mother
- make themselves - IgM
- make some of: IgA
- most from mother - IgG
How can HIV be transmitted from mother to child?
usually beyond 36 weeks
intrapartum
or
breastfeeding
How is HIV managed to reduce transmission during pregnancy and shortly after?
- Regular CD4 and viral load tes (low cd4 and high viral load most suceptible)
- HAART meds (highly active antiretovial therpay) and prophylaxis agains Pneumocystis carnii pneumonia
- C- section
- avoid breasfeeding
- HAART 1st 6 weeks of infants life
What causes candida infections?
candida albicans - commensual in mouth and GI tract
How do you manage oral thrush in children not immunocompromised?
Miconazole oral gel
What is a possible cause of oral candida in children and what should you advise? (5)
corticosteroid use
- advise good oral hygiene
- rinsing mouth with water after use
- good inhaler technique
- advise using a spacer
- consider stepping down dose where appropriate
How do you manage skin and vaginal candida?
imidazole for both
+/- pessary for vaginal
How does encephalitis in present?
- Flu like prodrome
- reduced consciousness
- odd behaviour
- vomiting
- fits
- fever
- meningism (headache, neck stiffness, photophobia)
What are possible causes of encephalitis?
- HSV
- mumps
- Varacilla zoster
- parvovirus
5 TB
What investigations should you do for encephalitis?
- CSF MC+S and PCR
- bloods
- stool (enteroviruses)
- urine
What causes toxic shock syndrome?
What else does this cause?
Group A staphylococcus aerus
Also causes staphylococcal scalded skin syndrome
How does toxic shock syndrome present? (4)
What is the management?
- Fever (39+)
- hypotension
- diffuse erythematous rash
- desquamation of rash - palms and soles
Emergency
- ABCDE
- O2
- IV broad spectrum Abx and IVIG
- IV fluids
- debridement
What do you expect to see in LP
- Appearance
- Proteins
- Glucose level
- White cell count
in Bacteria and Viral
Bacteria
- Cloudy
- raised proteins
- low glucose
- raised white cells - neutrophils
Viral
- clear
- mildly raised/normal proteins
- Normal glucose
- raised whit cell - Lymphocytes
What is the presentation of shingles?
acute unilateral painful blistering rash
does not cross midline
caused by reactivation of varicella zoster virus
What are the complications of shingles? (3)
- pneumonia
- encephalitis
- group A streptococcal skin infections
Advice for parents on nappy rash? (6)
- leave nappy off as much as possible
- change nappy often
- use wipes free from fragrance and alcohol
- dry bottom, not rub
- thin layer of barrier cream (zinc and castor oil ointment)
- mild steroid cream - hydrocortisone
NO TO TALCUM POWDER
What causes Roseola infatum?
Triad of presentation and other symptoms?
Age range?
Management?
Human herpes virus 6
High fever, maculopapular rash, convulsions (10-15%)
6months - 2 yrs
supportive, resolves on its own
Who does molluscum contagiosum present in?
What is the cause?
- often children with atopical eczma, 1-4 yr olds
2. viral skin infection - molluscum contagiosum virus
Key signs and symptoms of molluscum contagiosuM
What is the treatment?
flesh coloured papules
have a central dimple
very contagious
tx = topical wart meds e.g salicylic acid
goes away on its own in a year
What causes scabies?
Where is classical location of rash and where does it spread?
How long before symptoms appear?
super itchy (type IV hypersensitivity reaction), small red spots
classic location = fingerwebs, spreads to whole body, can take up to 8 weeks before symptoms appear
What causes scabies?
What is the management
Mites - burrow under skin and lay eggs
- wash ALL
- 5% premethrin cream - cover for 8 hours then wash off
- all household and close contacts all treated same
How does ringworm present?
Name ringworm in scalp, feet, groin, body?
itchy circular red scaly and well demarcated rash - fungal
scalp = tinea capitis feet = tinea pedis groin = tinea cruris body = tinea corporis
What is the management of ringworm?
What will make it worse?
antigfungal cream - Clotrimazole/miconazole
oral antifungal - fluconzaole
Streoid cream will make it worse!
