Viral skin infection

Question 1

What are some examples of viruses that can affect the skin?

Answer 1

• Herpes simplex virus
• Human papillomavirus
• Molluscum contagiosum (Poxvirus)
• Varicella-Zoster virus
• Viral exanthems

Question 2

What are some skin infections caused by Herpes Simplex Virus?

Answer 2

Oral warts (Cold sore)
Genital warts
Digital (Whitlow) warts

Question 3

How can HSV infection affect the nerves?

Answer 3

The HSV virus enters the epidermis and penetrates the endings of sensory and autonomic nerves, causing cell death, acantholysis and sensory nerve damage

This results in a localised vesicular rash and neuropathic pain

Question 4

What are some management options in HSV?

Answer 4

Acyclovir (Valacyclovir - Pro-drug)
Penciclovir (Famciclovir - Pro-drug)

Question 5

How do acyclovir and penciclovir act as anti-virals?

Answer 5

They both are converted into monophosphates, then triphosphates, which prevent DNA polymerisation and this prevent DNA synthesis

Question 6

What are some skin infections cased by HPV?

Answer 6

Peripheral warts
Genital warts (Condyloma acuminata)
Verrucas

Question 7

What are some cancers that HPV infection increases the risk of?

Answer 7

• Vulvar cancer
• Oropharyngeal cancer
• Penile cancer
• Cervical cancer
• Anal cancer

Question 8

How can COVID-19 affect the skin?

Answer 8

• Morbilliform rash
• “Covid toe” ( like a chilblain/ pernio like)
• Livedo reticularis ( lace like)
• Retiform purpura
• Urticaria
• Vesicular blisters ( like chicken pox)
• Telogen effluvium on recovery

Question 9

How can multi-system inflammatory disease in children as a result of COVID-19 affect the skin?

Answer 9

• Mucositis
• Swelling and redness of hands and feet
• Conjunctivitis
• Polymorphic erythematous rash

Question 10

What are the 4 main patterns of viral exanthem?

Answer 10

• Erythematous exanthems starting on the face
• Erythematous exanthems starting on the trunk
• Papulo-vesicular exanthems
• Exanthems of the extremitis

Question 11

What are some erythematous exanthems starting on the face?

Answer 11

• Measles
• Rubella
• Erythema infectiosum

Question 12

What are some erythematous exanthems starting on the trunk?

Answer 12

• Roseola
• Scarlet fever
• Unilateral laterothoracic exanthem

Question 13

What are some papulo-vesicular exanthems?

Answer 13

Varicella-Zoster (Chicken pox and shingles)
Gianotti-Crosti syndrome

Question 14

What is an exanthems of the extremities?

Answer 14

Hand, foot and mouth disease

Question 15

What virus causes measles?

Answer 15

Paramyxovirus

Question 16

What is the incubation period of measles?

Answer 16

1-3 weeks

Question 17

What are some classical symptoms of measles?

Answer 17

• Fever ≥ 39ºC
• Generalised maculopapular rash
• Conjunctivitis
• Cough
• Coryza
• Koplik spots (Prodrome)

Question 18

What are some complications of measles?

Answer 18

• Otitis media
• Laryngotracheobronchitis
• Febrile seizures
• Hecht’s giant cell pneumonia
• Appendicitis
• Myocarditis

Question 19

What is the mainstay in measles prevention?

Answer 19

Measles vaccination

Question 20

What are some side effects of measles vaccination?

Answer 20

Joint pain, fever, rash

Question 21

Why may patients not get the measles vaccine?

Answer 21

Patients may not get the MMR vaccine due to vaccine hesitancy (Related to Andrew Wakefield)

Question 22

What virus causes rubella?

Answer 22

Togavirus

Question 23

How will rubella present?

Answer 23

This will follow the same rash distribution as measles, however will be less red and lasts a shorter period of time

Question 24

What virus causes erythema infectiosum?

Answer 24

Human Herpes virus 6 (HHV-6)

Question 25

How will erythema infectiosum present?

Answer 25

This presents with a slapped cheek appearance, with a reticular (Lacy) pattern

Question 26

What is the name given to an initial infection of Varicella-Zoster?

Answer 26

Chicken pox

Question 27

What is the name given to a re-activation of Varicella-Zoster in the body?

Answer 27

Shingles

Question 28

Until what point is Varicella-Zoster infection contagious?

Answer 28

Until all lesions are crusted over

Question 29

Where does Varicella-Zoster remain in the body?

Answer 29

It becomes latent in nerve roots

Question 30

How does shingles occur?

Answer 30

The initial infection can become latent in nerve roots and in cases of immunosuppression or pregnancy, it becomes reactivated and spreads along a the nerve as shingles

Question 31

How will shingles present?

Answer 31

papilo-vesicular rash along one dermatome

Question 32

What are some possible complications of chicken pox?

Answer 32

- Bacterial sepsis - Pneumonia - Encephalitis - Haemorrhagic complications

Question 33

What are some possible complications of shingles?

Answer 33

- Meningoencephalitis - Myelitis - Cranial nerve palsy - Vasculopathy - GI ulceration - Pancreatitis - Hepatitis In around 15% of elderly patients, postherpetic neuralgia can occur

Question 34

What is Herpes-Zoster oticus (Ramsay-Hunt syndrome)?

Answer 34

This is a condition in which a shingles outbreak affects the nerves of the face, causing facial paralysis, hearing loss and a facial rash