Viral skin infections Flashcards
Chickenpox and shingles are both caused by which virus?
Varicella zoster
How does chickenpox present?
Typically in childhood the patient will present with a generalised itchy rash and fever
How does shingles present?
Dermosomal reactivation of the virus typically in old age
How does chickenpox become shingles?
The virus becomes latent after an episode of chicken pox and settles in the sensory nerve roots where it can reactivate at any time
What is the progression of the chickenpox rash?
Macules to papules to vesicles to scabs to recovery
How would you describe the chickenpox rash?
Inflamed erythematous polymorphic rash with centripetal distribution of varying density
What are the possible complications of chickenpox?
Secondary bacterial infection, VZ pneumonitis, hemorrhagic chickenpox, scarring, encephalitis
What are some predictors of the severity of chickenpox?
Extremes of age or immunosuppression
Neonatal chickenpox infection can occur when the mother is infected with the virus during pregnancy. T/F
True
How high is the mortality rate for neonatal chickenpox? How can it be prevented?
Very high. Immunoglobulin injections in susceptible woman
Who gets shingles the most?
Elderly and/or immunocompromised patients
What is the progression of the shingles rash?
Tingling/pain > erythema > vesicles > crusts
What type of pain does shingles give its victims?
Neuralgic
After four weeks of shingles related pain what is the pain then called?
Post herpetic neuralgia
How common is scarring of the skin from shingles?
Un
What are the three divisions of the trigeminal nerve called?
Ophthalmic, maxillary & mandibular
What department needs urgent referral if a patient present’s with ophthalmic shingles?
Ophthalmology
What complications can arise from ophthalmic shingles?
Optic scarring, red eyes, facial palsy
In what circumstances would children be more likely to get shingles?
Chickenpox in utero or immunocompromised
What is Ramsay-Hunt syndrome?
Vesicles and pain in the auditory canal and throat along with facial palsy and irritation of the eight cranial nerve causing deafness, vertigo and tinnitus
What is the other names for Ramsay-Hunt syndrome?
Geniculate or otic herpes zoster
What is Bell’s palsy?
Bell’s palsy is a condition that causes temporary weakness or paralysis of the muscles in one side of the face.
What type of vaccine is the chickenpox vaccine?
Live attenuated
What are the indications for chickenpox vaccine in the UK?
At risk health care workers
What are the indications for the shingles vaccine in the UK?
70>
What is the difference between the chickenpox vaccine and the shingles vaccine?
The shingles vaccine is just a higher titre preparation
What are the benefits of giving the shingles vaccine?
Reduces incidence of shingles and incidence of post herpetic neuralgia
How does herpes simplex virus present?
+ primary gingivostomatitis -extensive ulceration in and around mouth
+ recurrence - blistering rash at vermillion border
When does herpes simplex virus typically present and how long does it last?
Pre-school children. Lasts around a week
Where can herpes simplex virus be spread to?
Fingers (herpetic whitlow) and eczema (herpeticum)
What are the two types of herpes simplex virus and what are the differences between them?
Type 1 - mainly oral lesions and half of all genital cases, can cause encephilitis
Type 2 - rarely causes oral lesions, half of all genital cases, encephalitis/disseminated infection (neonates)
What is the treatment of varicella zoster virus and herpes simplex virus?
Aciclovir
What is the mechanism of action of aciclovir? What is the drawback of it?
Selectively incorporated into viral DNA to prevent replication. Does not eliminate latent virus
How can herpes simplex/varicella zoster be diagnosed?
Viral swab (skin/mucous membrane infections), antibody tests (virus infected site inaccessible)
What is erythema multiforme?
Erythematous target lesions
What can trigger erythema multiforme?
Multiple drugs, infections (e.g herpes simplex virus, mycoplasma pneumonia)
What is molluscum contagiosum?
Small, fleshy, firm, umbilicated, pearlescent nodes. Self limiting but months in duration.
Who gets molluscum contagiosum?
Children mostly
Molluscum contagiosum can be sexually transmitted. T/F
True
How can molluscum contagiosum be treated?
Application of liquid nitrogen
What causes warts?
Human papilloma virus
What group commonly gets warts?
Children
How can warts be treated?
Self limiting but topical salicylic acid can be used to speed up removal
What can be caused by HPV?
Warts, veruccas (type 1-4), genital warts (type 6 & 11), cervical cancer (type 16 & 18), head & neck cancer
What strains of HPV does the current UK vaccine protect against?
Types 6, 11, 16 & 18 (gardasil)
What is herpangina?
Self limiting blistering rash at the back of the mouth
What organisms cause herpangina?
Enterovirus (coxsackie & echovirus)
How can herpangina be diagnosed?
Swabs or stool for PCR
What is hand, foot and mouth disease?
Non-itchy erythematous vesicles on hands & feet as well as painful mouth ulcers
Where does the rash on hand, foot and mouth disease also develop?
Knees, elbows, buttocks & groins
Which virus causes hand, foot and mouth?
Enteroviruses (coxsackie)
Who typically gets hand, foot and mouth?
Children & their families
What is a complication of hand, foot and mouth caused by enterovirus 71?
Brain stem encephalitis
Name a viral cause of rash and acute arthritis. What does this look like?
Erythema infectiosum. Slapped cheek appearance > lacy macular rash on the body (children). No macular rash present but acute polyarthritis of the small joints (adults).
What virus causes slapped cheek disease?
Parvovirus B19
What are the possible complications of slapped cheek disease?
Foetal hydrops followed by spontaneous abortion, aplastic crises or chronic anaemia (in immunosupressed)
What is an aplastic crises? Who may experience this?
Sudden drop in haemoglobin. Patients with conditions giving short red cell lifespan who contract parvovirus B19
How is slapped cheek disease diagnosed?
Antibody testing (IgM test)
How does rubella present?
Diffuse erythema that blanches on pressure. After rash disappears there are often oral lesions & petechial haemorrhages on the soft palate. Systemic symptoms also
How is rubella diagnosed?
Antibody testing
How is rubella prevented?
Vaccination in high risk areas
How does orf present?
Firm, fleshy nodules on the hands
How is orf diagnosed? How is it treated?
Clinically. Self-limiting
How is orf contracted? Who usually gets it?
Sheep. Farmers
How does primary syphillis present? How does secondary syphillis present? How does tertiary syphilis present?
Chancres (painless ulcers) at site of entry. Red rash all over the body & most prominent on palmer/planter surfaces as well as mucous membrane snail track ulcers. CNS, CVS, gummatous, etc symptoms.
What is the cause of syphilis? How is it spread?
Treponeum pallidum (BACTERIA). Sexually
How is syphilis diagnosed?
Bloods or chancre swab for PCR
How is syphilis treated?
Penicillin injections
How does lyme disease present?
Erythema migrans > heart block, nerve palsies & arthritis
What is the cause of lyme disease?
Borrelia burgdorferi hosted inside ticks
How is lyme disease diagnosed?
Clinical but in later stages antibody blood test
How is lyme disease treated?
Doxycycline or amoxicillin
Tick bites are treated with prophylactic antibiotics. T/F
False - asymptomatic bites are left alone
