Chapter 34 - Other Vesiculobullous Diseases

Question 1

Do the blisters of bullosis diabeticorum occur on the background of normal or inflammed skin?

Answer 1

They appear on normal-appearing skin

Question 2

What type of diabetes has bullosis diabeticorum been associated with?

Answer 2

Both type 1 and type 2 diabetes

Question 3

Do the blisters of bullosis diabeticorum occur slowly or rapidly?

Answer 3

Rapidly, often developing “overnight”

Question 4

Is DIF generally positive or negative in bullosis diabeticorum?

Answer 4

Usually negative (although deposits of IgM and C3 can sometimes occur in dermal blood vessels)

Question 5

How long does it usually take for blisters of bullosis diabeticorum to heal?

Answer 5

Between 2-6 weeks (they heal spontaneously)

Question 6

Do coma blisters usually occur at sites of pressure or at sites without pressure?

Answer 6

Sites of pressure

Question 7

What is the most commonly implicated drug-induced coma with coma blisters (i.e. the specific drug involved)?

Answer 7

Barbiturates, although other drug-induced comas have been implicated (e.g. opiods), as well as non-drug-induced comas (e.g. infection, CVAs, etc.)

Question 8

Does a patient have to be in a coma to develop coma blisters?

Answer 8

No, they can occur in patients that are chronically immobilized or have neurologic diseases

Question 9

What is the classic histologic finding associated with coma blisters, other than subepidermal blisters?

Answer 9

Eccrine coil necrosis (presumably due to drugs excreted through the eccrine coil)

Question 10

Do coma blisters heal spontaneously?

Answer 10

Yes, within 1-2 weeks if the patient survives

Question 11

Will DIF be positive or negative in biopsies of coma blisters?

Answer 11

Negative

Question 12

Where is the histologic level of the split in friction blisters?

Answer 12

Just below the stratum granulosum

Question 13

Does moist or dry skin provide higher frictional forces?

Answer 13

Moist skin does, thus it’s more prone to friction blisters than dry skin

Question 14

If a friction blister contains blood-tinged fluid, should you reconsider your diagnosis?

Answer 14

Not necessarily; friction blisters often contain serosanguinous fluid

Question 15

True or false: it’s appropriate to fully de-roof a friction blister.

Answer 15

False; this increases the risk of infection; it’s best to create a small “window” to avoid fluid reaccumulation, leaving the remainder of the blister roof to act as a physiologic dressing

Question 16

True or false: some drug eruptions can present as blistering eruptions.

Answer 16

True

Question 17

Can a small vessel vasculitis produce bullous lesions?

Answer 17

Yes

Question 18

In which two patient populations are bullous insect bites most common?

Answer 18

In children and in adults with CLL

Question 19

True or false: both humoral (type I, IgE-mediated) and cell-mediated (type IV, delayed hypersensitivity) immunity are involved in the response to insect bites.

Answer 19

True

Question 20

Which type of insect bite is most likely to produce a bullous reaction (i.e. what type of insect)?

Answer 20

Flea bites

Question 21

Can insect bites ever be pustular?

Answer 21

Yes, for example the bites of fire ants can be pustular

Question 22

Histologically, flame figures are occasionally seen on biopsies of insect bites (particularly in patients with CLL). What are flame figures?

Answer 22

Eosinophilic granules that have covered collagen fibers

Question 23

With respect to delayed postburn/postgraft blisters, is it just the burned/grafted skin that’s affected? Or can the adjacent normal skin also be affected?

Answer 23

It’s only the burned/grafted skin that’s affected

Question 24

What are blisters that occur in the context of chronic lymphedema called?

Answer 24

Edema blisters

Question 25

If PUVA-induced acrobullous dermatosis occurs, should PUVA therapy be stopped?

Answer 25

No, there’s in no need to interrupt PUVA therapy

Question 26

What is bullosis diabeticorum usually associated with?

Answer 26

Diabetes mellitus (type 1 or 2), with peripheral neuropathy, retinopathy or nephropathy

Question 27

Which anatomical locations are most commonly affected by bullosis diabeticorum (in decreasing order)?

Answer 27

Feet, lower legs, hands, forearms

Question 28

What is the treatment for bullosis diabeticorum?

Answer 28

Spontaneous healing in 2-6wks. Treat as any blister (eg. aspirate, de-roof, prevent infection)

Question 29

What are coma blisters usually associated with?

Answer 29

Coma, neurologic diseases, blisters in 2-3d usually at pressure sites

Question 30

What are predisposing factors of friciton blisters?

Answer 30

Poor fitting shoes, heat, sweat

Question 31

What are the 8 different types of bullous drug eruptions?

Answer 31

1) Fixed drug eruption, 2) SJS/TEN, 3) LABD/pemphigus/BP, 4) pseudoporphyria, 5) AGEP, 6) phototoxicity, 7) bromoderma/iododerma, 8) palmar plantar erythrodysesthesia

Question 32

Who are more likely to develop bullous insect bite reactions?

Answer 32

Children, those with chronic lymphocytic leukemia

Question 33

What % of BSA involvement is commonly found in patients who develop delayed postburn blisters?

Answer 33

30%

Question 34

When do delayed postburn/postgraft blisters develop?

Answer 34

2-3 days or weeks after complete healing

Question 35

What are some risk factors for development of edema blisters?

Answer 35

Elderly, immobile, anasarca, whenever there is acute exacerbation of chronic edema

Question 36

What is the pathogenesis of PUVA induced acrobullous dermatosis?

Answer 36

Chronic PUVA induced weakening of the epidermal-dermal cohesion + friction/trauma, usually on distal limbs