Infectious diseases Flashcards
What would you advise to a mother about their child’s exclusion from school as he has chicken pox?
Exclude from school until all lesions crusted over
A 70 year old man comes into clinic complaining of a very painful rash on his face. It’s sore to touch and you notice the rash is only one side of his face around his eye area and spreads no further. What is the diagnosis and how do you treat?
Shingles
PO aciclovir
2 months later, the same man you diagnosed and treated his shingles returns with continuous pain. He struggles to describe the pain but says its stabby and no medication has helped. There are no signs of a rash anymore. What is the diagnosis and what can you give?
Post-herpetic neuralgia.
Tx: amitryptilline, gabapentin, pregabalin
A 25 year old comes to clinic complains of these new sores on her mouth. They are quite painful and are causing some trouble with drinking. A couple of them having began to ulcerate. On examination, you see vesicles around the mouth. What is the diagnosis and treatment?
Herpes simplex virus- commonly 1 (2= genital)
Tx: acyclovir oral
You see a patient who has new onset little pink papules that have a dimple in the centre. They are spread all across the body. Patient is feeling completely well. What is the likely diagnosis?
Molluscum contagiosum
A 45-year old man, who works as a fishmonger, presents with a 3 day history of diarrhoea and vomiting. Diarrhoea 10x per day (no blood or mucous) and vomiting hourly. He went to a new restaurant the day before with work, and his co worker now has similar symptoms. He has no other infectious contacts and he has never travelled outside of yorkshire.
No relevant PMH or DH.
What is the diagnosis and commonest causative organism?
Diagnosis: gastroenteritis
Commonest causative organism: viral - rotavirus
bacterial: campylobacter- gram -ve bacilli
Which organism would you expect if the man added that actually the diarrhoea is bloody and you took some blood tests which showed a raised creatinine and urea? What has he developed and what is it about this organism that causes it?
E.coli- bloody diarrhoea and releases shiga toxin which causes a HUS
What advice should you give that fishmonger with gastroenteritis?
Stay off work until 48 hours after symptoms resolved?
What are the 3 main bacterial causes of bloody diarrhoea?
Campylobacter, shigella and salmonella (egg and poulty)
What is the pathogen causing watery diarrhoea and abdominal cramps due to eating gone off rice?
Bacillus
A 80 year old woman who was just in hospital for pneumonia where she was treated with antibiotics presents to GP 3 days later with watery diarrhoea and abdominal cramps. What is the likely diagnosis and treatment?
C.diff infection
Tx: vancomycin/metronidazole
A medical student returning from their elective travelling across Africa presents to you in GP with
fever and headache. She was ‘fully vaccinated’ prior to her trip and took Chloroquine and Proguanil anti-malaria prophylaxis.
Despite this you suspect malaria
What specific insect bit this student and what parasite are they now infected with?
Female anopheles mosquito
Parasite: plasmodium falciparum is the most common
What symptoms could someone with malaria present with?
Fever, sweats Headache Lethargy, malaise Jaundice - haemolytic Nausea and vom Abdo pain
What are other parasites causing malaria - other than plasmodium falciparum ?
P.ovale
P.vivax
P.malariae
What is the gold standard investigation in malaria? What might you see on bloods?
thick- counts parasites and thin- identifies species blood films
Blood tests: haemolytic anaemia- low Hb, raised bilirubin, platelets low
How do you manage malaria? falciparum v other types
Admit to hospital
Falciparum- uncomplicated: quinine + doxy. If severe/complicated: IV artesunate
Other types: chloroquine
Notify PHE
What drug is used as meningitis prophylaxis for close contacts?
Ciprofloxacin or rifampicin
What is the commonest cause of encephalitis?
Viral- herpes simplex
How do you investigate a patient with encephalitis?
Blood cultuyres
MRI brain
LP - lymphocytes, normal glucose, high protein
You are working in A&E and a patient has been a big trauma and has open dirty wounds. He doesn’t know if he’s had the tetanus vaccine. What do you do?
clean wound and Give tetanus vaccine
You are working in A&E and a patient has been a big trauma and has open dirty wounds. He doesn’t know if he’s had the tetanus vaccine. He now has developed some spasms in his body which are painful. What has happened and how will you treat?
Tetanus clean wound Antibiotics Tetanus immunoglobulin- he has symptoms Benzo's - relax muscles
A 20 year old plumber admitted with a 3 day history of painful swelling of his left leg feeling generally unwell with episodes of fevers and rigors.
o/e temperature of 38oC, pulse rate 108/min and blood pressure 120/80 mmHg.
Marked area of swelling and erythema over his left shin spreading towards the ankle and knee. Warm and tender to touch. palpable and tender inguinal lymph nodes. no obvious breaks to the skin of his legs or feet
What do you think the diagnosis is?
Cellulitis
What investigations do you want to do in a patient with cellulitis?
Bloods: FBC, U&E, CRP, blood cultures
Skin swabs
What are the most common causative organisms of cellulitis?
Staph aureus
Beta haemolytic strep
How do you treat cellulitis? if penicillin allergic?
Flucloxacillin
pen allergic: clindamycin
You see a patient with swelling and erythema over left shin., Warm and tender to touch. What features would make you be more worried it’s nec fasc, and what would you do if they were present?
Dark blue/purple discolouration to skin Crepitus felt on palpation Severe pain Systemic upset- fever, N&V, tachycardia Mx: bloods and blood cultures, IV fluids, oxygen and urgent surgical debridement and IV abx broad spec eg. pencillin/clindamycin
What are the pathogens that cause nec fasc?
Group A beta haemolytic strep
Clostridium perfringens - gas gangrene
