Infections Flashcards
(23 cards)
Describe streptococci
Gram positive cocci
Treated with penicillin
No resistance issues
Describe staphylococci
Gram positive cocci
Treated with flucloxacillin (= synthetic penicillin resistant to B-lactamases)
Resistance major issue (MRSA)
Describe scarlet fever
Typical group A strep infection, most commonly in children under 10
2-4day incubation Malaise, fever, pharyngitis Rash (peri-oral sparing) Strawberry tongue Desquamation (hands, feet)
Describe group A strep
Carriage upper resp tract 10% population
Uncommon in children <2 and >10
Complicated presentation in immunosuppressed and chicken pox
Virulence factors; M-protein, exotoxins, invasins
Treatment; penicillin 10 days
What are some virulence factors in group A strep?
M-protein
Exotoxins
Invasins
what are complications of group A strep infection?
Impetigo Erysipelas Necrotising fasciitis Rheumatic fever (target lesion rash) Glomerulonephritis
What skin infections and serious systemic disease can be caused by staph aureus?
impetigo Cellulitis Infected eczema ulceration Staph scalded skin syndrome toxic shock syndrome
Describe staph scalded skin syndrome
Typically S.aureus
Msotly kids <5 (esp newborns)
Fever, widespread redness, fluid-filled blisters, rupture easily, esp in skin folds
Describe toxic shock syndrome
S.pyogenes/S.aureus
Systemically unwell
Widespread redness, desquamation, multi-organ involvement
Rapidly fatal
Describe Kawasaki disease
Self-limited vasculitis of medium sized arteries
Unknown aetiology - infectious cause suggested
Leading cause heart disease in developed world -
Fever for 5 days +
- bilateral conjunctival injection
- cracked lips/strawberry tongue
- cervical lymphadenopathy >1.5cm
- polymorphous rash
- changes extremities
May present early/incomplete especially in infants
Clinical diagnosis
Treatment of kawasaki disease
Prevent complications; coronary aneurysms
Immunoglobulins Aspirin Steroids Other immunosuppressive agents Cardiology assessment
How can you differentiate rashes in children?
Erythematous; measles, rubella, enterovirus, cytomegalovirus, herpes 6/7, parvovirus, EBV
Vesiculobullous; VZV, herpes simplex virus, enterovirus
Petechial and purpuric; rubella, (congenital), cytomegalovirus (congenital), enterovirus
Describe VZV infections
Primary; varicella, chickenpox
Recurrent; zoster
Incubation period; 10-21 days (14)
Clinical; mild malaise and fever, itchy
Complications; secondary strep/staph infections skin, meningoencephalitis, cerebellitis, arthritis
Therapy; aciclovir if immunosuppressed or severely unwell
Describe fatal varicella
<1yr age
Immunodeficiency esp T cell
Warning signs; high fever, new lesions >day 10, inflamed lesions, general malaise
Describe HSV infections
HSV1 = oral HSV2 = genital
Stomatitis - recurrent cold sores
Complications;
- keratoconjunctivitis
- encephalitis
- systemic neonatal infections
therapy;
- self-limiting
- aciclovir
Describe neonatal HSV infections
Birth canal/direct contact
Day 4-21 of life
70-80% disseminated/CNS infections
- sepsis
- meningoencephalitis
- hepatitis
20-30% skin/eye/mouth
High mortality
Aciclovir
Describe hand foot and mouth disease
Enterovirus; Coxsackie A16
Children <10
Summer/early autumn
Incubation 3-6days
Clinical; erythema, painful lesions, recovery 5-10 days
May cause complicated illness in neonates
What are investigations for immunodeficiency?
FBC Immunoglobulins HIV test Functional antibodies Lymphocyte subsets NBT Complement
What are worrying warning signs of primary immunodeficiency?
Family history
Deep seated skin infection, IV antibiotics
Serious Persistent Unusual (causative organism) Recurrent Family history
Describe paediatric HIV infection
Vast majority vertically transmitted
Mothers antenatally screened
Mothers advised not to breastfeed
Mothers receive anti-retroviral therapy, baby receives prophylaxis
how can antibody deficiency present?
Defective B cell function
recurrent bacterial infections
Check immunoglobulins
How can cellular immunodeficiencies present?
Impaired or absent T cell function
Unusual or opportunistic infections
Recurrent /severe viral infections, FTT
How can innate immune disorders present?
Defects in phagocyte function
Sepsis, abscess, fungal infections
Complement deficiencies present w/sepsis so check complement if sepsis concern
