Blisters

Question 1

What is difference between vesicle and a bulla?

Answer 1

Diameter

Question 2

What is the difference between an erosion and ulcer?

Answer 2

Depth

Question 3

Vesicles or bullae can be filled with…?

Answer 3

Blood (Presence of hemorrhage)

Question 4

What are the definitions of bullae, vesicle, erosion, crust?

Answer 4

Vescicle=Small blister
Bulla=Large blister
Erosion=After blisters unroof
Crust=Dried transudate

Question 5

What are causes of blisters forming?

Answer 5

Trauma, infection, inflammation in upper levels of skin.

Question 6

When top of blister is disrupted it forms…?

Answer 6

An erosion or ulceration and oozes serous fluid to form a crust.

Question 7

What are typical features of shingles infection?

Answer 7

Shingles/Herpes zoster
Dermatomal eruption, unilateral.
Grouped vesicles on erythematous base (typical of herpes family of viruses including VSV).
Preceded by pain or burning.
Occurs only once in immunocompetent, whereas HSV recurs.

Question 8

What does acral mean?

Answer 8

On distal extremities (hands and feet)

Question 9

What does arcuate mean?

Answer 9

In curve or arc

Question 10

What does linear mean?

Answer 10

In straight lines

Question 11

What does intertriginous mean?

Answer 11

In body folds

Question 12

What causes shingles?

Answer 12

Eruption of latent varicella zoster virus

Question 13

Treatment of shingles?

Answer 13

Acyclovir or valacyclovir can decrease length of eruption and post-herpetic neuralgia.

Question 14

Typical features of herpes simplex?

Answer 14

Recurrent in same place.
Vesicles on erythematous base.
Pustular vesicles (white to yellow). HSV 1 favors mouth and nose.
HSV 2 favors genitalia, buttocks, thighs.
Perianal erosions or ulcerations in immunosuppressed patients are usually HSV.
Only erosion may be present at presentation.

Question 15

Vesicles in bathing suit distribution.

Answer 15

These are HSV until proven otherwise (on genitalia, buttocks, thighs).

HSV has bright red borders (may present as pustules or erosions).

Question 16

Severe perianal HSV may occur in…?

Answer 16

HIV or other immunosuppresion.

Question 17

Single genital ulcers could be…?

Answer 17

Syphilis or chancroid.

Question 18

What occurs when there is a vesicle on notched distal interphalangeal digit?

Answer 18

Herpetic whitlow.

Question 19

What tests can you use for herpes family viruses?

Answer 19

Tzanck prep (bedside scraping and microscopic exam=Cannot differentiate VZV and HSV).

Viral culture (performed when fluid present; less helpful once crust forms. Results in 1-3 weeks. Not helpful for VZV).

Direct fluorescent antibody (DFA) test: Can differentiate HSV 1, HSV 2, VZV. Scrape base of vesicle or erosion. Results in 48 hours.
HSV antibody detection determines past exposure. May not directly related to clinical findings.

Fluid swab for PCR is rapid and sensitive test that differentiates HSV1, 2, and VZV. Test of choice at UNC.

Question 20

HSV treatment?

Answer 20

Acyclovir (safe, cheap, reliable).
Can be used episodically or prophylactically.

Acyclovir: Can be used in pregnancy.

IV acyclovir is available for generalized HSV or VZV in immunocompromised.

Famciclovir and valacyclovir are more expensive but have easier dosing.

Question 21

Dyshidrotic eczema: Features

Answer 21

Pruritic vesiculopapules on palms, soles, sides of fingers. AFFECTS HANDS AND FEET.

Vesicle fluid has been compared to tapioca pudding.

Many patients have history of atopic dermatitis and have coexisting tinea pedis.

Question 22

Dyshidrotic eczema: After healing, what happens?

Answer 22

After healing, they leave behind mark with mahogany color called post-inflammatory hyperpigmentation.

Question 23

Dyshidrotic eczema: Treatment

Answer 23

Potent topical steroids

Question 24

Vesicles on dorsal foot: Differential

Answer 24

Contact dermatitis, insect bites

Question 25

Vesicles on sides of feet and toes

Answer 25

Dyshidrotic eczema

Question 26

Vesicles on soles of feet

Answer 26

Tinea pedis (often with scaling and interdigital maceration)

Question 27

Vesicles on balls, heels

Answer 27

Friction blisters

Question 28

Pain precedes onset of vesicles

Answer 28

HSV, VZV

Question 29

Itch precedes onset of vesicles

Answer 29

Allergic contact dermatitis, dyshidrotic eczema, VZV

Question 30

Trauma precedes onset

Answer 30

Friction blister, pressure ulcer, cyrotherapy

Question 31

Recurrent blisters

Answer 31

HSV

Question 32

Chicken pox: Features

Answer 32

Primary varicella zoster virus infection.

Diffuse vesicles on erythematous base, various stages of healing.

Can be extensive and severe, especially in adults.

Disseminated reactivated zoster can be identical.

Diagnose by PCR, DFA, culture, or Tzank..

Question 33

Pemphigus vulgaris: Features

Answer 33

Autoantibodies to desmogleins 1 and 3 between keratinocytes resulting in superficial bullae and erosions.

Usually in elderly.

Diagnose with direct immunofluorescence.

Consult dermatology.

Question 34

Bullous pemphigoid: Features

Answer 34

Autoantibodies to hemidesmosome resulting in deep, tense bullae on pruritic, urticarial base.

Split between basement membrane and basal layer.

Usually in elderly.
BPAG2 antibodies found with direct immunofluorescence.

Question 35

Drug eruptions cause…

Answer 35

These appear acutely and can lead to vesicles, bullae, and large erosions.

Question 36

Generalized vesicles and bullae represent ______ and ________ disease.

Answer 36

Severe and potentially fatal.

Question 37

How would you test for autoimmune bullous diseases?

Answer 37

Biopsy for direct immunofluoresence

Question 38

How would you differentiate between herpes simplex and shingles?

Answer 38

Direct fluorescent antibody test.

Question 39

What does a positive Tzanck prep mean?

Answer 39

Positive test=Non specific for herpes family of viruses.

Question 40

Best treatment of herpes simplex vesicles around mouth?

Answer 40

Oral acyclovir

Acyclovir ointment (Topical antivirals are relatively ineffective compared to oral antivirals.)