Bacterial and viral infections

Question 1

What is commensal bacteria?

Answer 1

Bacteria present on skin but not causing disease

Question 2

What are some examples of commensal bacteria?

Answer 2

Staphylococci MicrococciCorynebacteria Propionibacteria

Question 3

Does staph aureus cause disease?

Answer 3

ALWAYS regarded as pathogenic May be commensal Disease associated with direct invasion of epidermis, hair follicle or production of toxin

Question 4

Does streptococcal infection causes disease?

Answer 4

Always pathogenic Acute onset and rapid spreadSimilar disease to staph May co-infect with staph

Question 5

What are the six main types of bacteria which cause clinical skin infection

Answer 5

staphylococcistreptococcipseudomonas aeruginosacorynebacteriummycobacterium and atypical mycobacteria spirochetes

Question 6

What are different skin conditions caused by PRIMARY infection with staph. aureus?

Answer 6

impetigo ecthyma folliculitisfuruncle carbuncle cellulitis sycosis

Question 7

What are different skin conditions caused by SECONDARY infection with staph. aureus?

Answer 7

infected atopic eczema infected wounds infected leg ulcers

Question 8

What investigations should be carried out in suspected staph infection?

Answer 8

skin swabs blood cultures - normally only positive in severe sepsis due to s.aureus septicaemia

Question 9

How should S.Aureus infection be treated topically?

Answer 9

mupirocinfuscidic acid

Question 10

How should S.Aureus infection be treated orally/IV?

Answer 10

flucloxacillin oral/ivoral erythromycin

Question 11

What disease are due to PRIMARY infection from group A streptococci?

Answer 11

cellulitis erysipelas perianal cellulitis necrotising fascitis

Question 12

What disease are due to SECONDARY infection from group A streptococci?

Answer 12

infected atopic eczema leg ulcers

Question 13

What disease due to Group A Streptococcal toxins?

Answer 13

Scarlet fever and rarely Toxic-Shock-Like-Syndrome

Question 14

What diseases due to allergic hypersensitivty to Group A streptococcal toxins?

Answer 14

erythema nodosum erythema multiformevasculitis glomerulonephritis

Question 15

How should strep be treated?

Answer 15

topical antibiotics not recommended oral amoxycillin/penicillin/erythromycin IV benzylpenicillin

Question 16

When pseudomonas considered pathogenic?

Answer 16

only considered pathogenic when skin is damaged

Question 17

What skin disease are caused with pseudo mans aeruginosa infection?

Answer 17

secondary colonisation and infection of leg ulcers or burnspseudomonal paronychia +/- infection of toe web spaces gram negative folliculitis

Question 18

What is the topical treatment for pseudomonas?

Answer 18

flamazine (silver sulphadiazine), 1% acetic acid soaks

Question 19

What is the oral treatment for pseudomonas?

Answer 19

ciprofloxacin

Question 20

How does corynebacterium infection cause disease?

Answer 20

erythrasma pitted keratolysis

Question 21

What sort of diseases are caused by mycobacteria and atypical mycobacterial?

Answer 21

cutaneous tuberculosis - lupus vulgaris mycobacterium leprae - leprosy atypical mycobacterium barium - fish tank granuloma

Question 22

What are the spirochaete infections?

Answer 22

syphilis lyme disease

Question 23

What are the clinical signs of impetigo?

Answer 23

isolated skin lesions with yellow-crusted surface often located around the mouth, nose, limbs

Question 24

What is the treatment for impetigo?

Answer 24

topical mupirocin is only partially and oral flucloxacillin should be prescribed

Question 25

What are the different types of viral wart?

Answer 25

plantar warts common warts plane wartsfiliform wartsmosaic wartsanogenital warts

Question 26

What is the prognosis and treatment of viral warts?

Answer 26

most spontaneously resolve other treatment options include topical paints cryotherapy curettage and cautery formalin soaks and podophyllin warts shouldnt be excised as they often recur

Question 27

What are the clinical presentations of Herpes Simplex Virus?

Answer 27

Cold sores Genital herpes

Question 28

How do cold sores present?

Answer 28

commonly affect the vermillion border of the lip start with pain and tingling and then erupt primary incubation period is 5 days

Question 29

How do genital herpes present?

Answer 29

first attack is most severe with significant pain, discomfort and vesiculation occurring after prodromal pain and tingling recurrence likely

Question 30

What are the potential complications of herpes infection?

Answer 30

herpes gingivostomatitis keratoconjunctivitis bells palsy eczema herpeticum erythema multiformeDissemiated HSV

Question 31

How should cold sores be treated?

Answer 31

topical acyclovir rarely systemic treatment

Question 32

How should genital herpes be treated?

Answer 32

oral acyclovir for a minimum of 5 days

Question 33

How does varicella-zoster virus present?

Answer 33

Chicken pox Shingles

Question 34

How does chicken pox present?

Answer 34

children develop headache, fever, malaise for 24-48 hours followed by onset of vesicles on trunk, face or scalp

Question 35

What are the complications of chicken pox?

Answer 35

Pregnancy - in first 20 weeks there is 2% risk of foetal damage Pneumonia Hepatitis Encephalitis Disseminated infection

Question 36

What is the treatment for chicken pox?

Answer 36

Adults, immunocompromised or patients on prednisone require oral aciclovir for 5-7 days

Question 37

How does shingles present?

Answer 37

pain and tingling for 24-48 hours precede a dermatomal eruption of vesicles

Question 38

What are the complications of shingles?

Answer 38

Post-herpetic neuralgia - persistent for more than 3 months Secondary infection Motor nerve palsy - facial (facial palsy, ear pain) or vestibulocochlear nerve (sensor neural deafness, dizziness, vertigo) Eye complications - conjunctivitis, ileitis Encephalitis and meningoencephalitis

Question 39

What is ORF?

Answer 39

caused by paradox virus and widespread in lambs/goats

Question 40

How does ORF present?

Answer 40

usually seen in farmers, vets or those who have come into contact with affected animals initial incubation is 5-6 dayssmall reddish purple papule on finger which blister

Question 41

How is ORF treated?

Answer 41

Usually self limiting but secondary infection might require oral fluconazole

Question 42

How does Human Papilloma Virus present?

Answer 42

Viral warts