Common viral rashes

Question 1

Papule

Answer 1

Elevated, solid region, <1cm

Question 2

Macule

Answer 2

Flat, solid region, <1cm

Question 3

Patch

Answer 3

Flat, solid region >1cm

Question 4

Plaque

Answer 4

Flat, elevated region, >1cm

Question 5

Nodule

Answer 5

Elevated, solid lesion, >1cm

Question 6

Vesicle

Answer 6

Elevated, fluid-filled lesion, >1cm

Question 7

Pustule

Answer 7

Elevated, pus-filled lesion >1cm

Question 8

Bulla

Answer 8

Elevated, fluid-filled lesion >1cm

Question 9

How to describe a rash

Answer 9

• Size
• Shape
• Colour - erythematous/purpuric/hyper- or hypo- pigmented
• Border - well demarcated or irregular
• Morphology - macular/papular/nodular/pustular
• Secondary morphology - scaly/eroding/ulcerating/fissuring
• Distribution

Question 10

Shingles

Answer 10

Caused by varicella zoster
Itchy, painful, blistering rash
Common in older patients, cancer patients and immunocompromised
Can spread to eyes and cause scarring and blindness
Start acyclovir (antivirals)

Question 11

Molloscum contagious

Answer 11

Itchy, highly contagious rash with pearly white papule and umbilicate appearance
Common in children and immunodeficient
Facial molloscums = AIDS
Tx: conservative, most will self resolve

Question 12

Coxsackie virus

Answer 12

Hand, foot and mouth
Enterovirus
Highly infectious, causes mild illness
Tx: analgesia for oral lesions

Question 13

Pityriasis rosea

Answer 13

Potentially caused by herpes - unknown
‘Herald patch’ before onset of x-mas tree pattern rash
Itchy byt asymptomatic
Antihistamines if needed

Question 14

Erythema infectiosum

Answer 14

Parvovirus B19
‘Slapped chee’ appearance, generally self limiting in young children but can cause arthropathy in adults, aplastic anaemia in pts with blood disorders and causes spontaneous abortion in pregnant women
Rash = not infectious
Causes abortion if contract in first trimester

Question 15

Microbes increasing risk of spontaneous abortion

Answer 15

Tozoplasmosis, rubella, HSV

Question 16

When do you get your 2 MMR vaccines

Answer 16

1st dose at 12 months, 2nd at 3y4m

Question 17

Measles

Answer 17

Measles morbillivirus

• 4 phases: incubation (7-14 days, no sx), prodrome (10-12 days, fever, malaise, conjunctivitis, spots and cough), exanthem (4-5th day, rash appears on face or behind ears and fades within 3-4 days) and recover (cough for 1-3 weeks)
• Dx: swab for PCR, blood IgM and IgG
• starts in mouth and spreads to rash within 2 days
• rarely affects palms and soles of feet

Question 18

Rubella

Answer 18

Rubivirus
Asymptomatic bar rash starting on face
Infectious from 7 days pre-rash to 7 days post
Intra-uterine death, abortion and birth defects
Analgesia, fluids and isolation

Question 19

Mumps

Answer 19

Rubulavirus
Highly infectious - incubation 14-25 days
Swelling of parotid glands
Usually no rash 
Analgesia and fluids

Question 20

Oral HSV

Answer 20

Oral caused by HSV 1, genital by HSV2
Sx: fever, malaise, sore throat, paraesthesia
- Complications: dehydration, herpetic whitlow, eczema
- Only consider oral antivirals in severe infections or immunocompromised peoplpe