Basement Membrane Zone and Vesiculobullous Diseases

Question 1

What are the 4 parts of the Basement Membrane?

Answer 1

1) the plasma membrane and hemidesmosomal plaques of the basal keratinocyte
2) lamina lucida
3) lamina densa
4) sublamina densa

Question 2

What is BPAG-2?

Answer 2

a transmembrane protein made up of XVII collagen

Binds to BPAG1 and integrins (in hemidesmosomes) with laminin 5 located in the laminin 5 located in the lamina densa

Question 3

What is BPAG-1?

Answer 3

an intracytoplasmic protein located within the cytoplasm of the basal keratinocyte hemidesmosomes
binds to keratin intermediate filaments to stabilize the cell

Question 4

What layer of the basement membrane does the BPAG-2 transverse?

Answer 4

lamina lucida

Question 5

What is the lamina densa composed of?

Answer 5

Laminins and collagen IV

Question 6

What is the key laminin found in the BMZ?

Answer 6

laminin 5

Question 7

Where is Type IV collagen located?

Answer 7

lamina densa

Question 8

What type of collagen is found in the sublamina densa?

Answer 8

Type VII

Question 9

What are immunobullous diseases?

Answer 9

inflammation of cells in the epidermis or BMZ

Leads to loss of cell-to-cell adhesion and subsequent bulla formation

Question 10

What are congenital mechanobullous diseases?

Answer 10

There is an absence of structural proteins that prevent normal cell-cell adhesion and promotes blister formation.

Question 11

What is the Nikolsky sign?

Answer 11

Apply gentle pressure to the edges of a blister and pull laterally to determine if a bulla is flaccid or tense

Question 12

Where is a DIF sample taken from?

Answer 12

perilesional site

Question 13

What is IIF?

Answer 13

It tests serum for circulating antibodies

Question 14

A serological test (DIF) for pemphigus vulgaris is testing against what?

Answer 14

IgG antibodies directed against Dsg 1 and 3

Question 15

A serological test (DIF) for bullous pemphigoid is testing against what?

Answer 15

BPAG1 and 2

Question 16

Describe common features of Pemphigus vulgaris

Answer 16

autoimmune blistering disease characterized by flaccid bullae and erosions
oral erosions
crusting of scalp
PAINFUL

Question 17

what will you see histologically in PV?

Answer 17

the basal keratinocytes remain connected to the BMZ resulting in a “tombstoning” appearance

Question 18

What is the treatment for PV?

Answer 18

systemic steroids and immunosuppressents

Question 19

Describe common features of Bullous Pemphigoid (BP)

Answer 19

typically affects adults 60+
itching
tense bullae

Question 20

What does a DIF of BP reveal?

Answer 20

a linear staining of the basement membrane with IgG and C3

also seen in CP

Question 21

What is the treatment for BP?

Answer 21

high potency topical steroids and oral antibiotics; severe cases may require immunosuppressants

Question 22

Describe common features of Cicatrical Pemphigoid (CP)

Answer 22

90% have oral symptoms, 66% have ocular symptoms, and 25 skin (flaccid bullae)
chronic
PAINFUL

Question 23

what is the treatment for CP?

Answer 23

potent topical corticosteroids and oral immunosuppressants

Question 24

What are antibodies directed against in CP?

Answer 24

BPAG2 and laminin 5

Question 25

What causes inherited mechanobullous diseases?

Answer 25

congenital absence of proteins in the BMZ

Question 26

What is Epidermolysis Bullosa (EB)?

Answer 26

a group of diseases with bullae and mechanical fragility of the skin

Question 27

What is Epidermyolysis Bullosa simplex?

Answer 27

an autosomal dominant disease where epidermal keratins are absent

Question 28

What is junctional Epidermyolysis Bullosa?

Answer 28

An autosomal recessive disease with laminin and BPAG2 mutations in the lamina densa

Question 29

What is dystrophic Epidermyolysis Bullosa?

Answer 29

an autosomal dominant and recessive disease where collagen VII is absent or abnormal

Question 30

Why does Epidermyolysis Bullosa have a high mortality rate?

Answer 30

increased risk of squamous cell carcinoma

Question 31

What disease is associated with celiac disease?

Answer 31

Dermatitis Herpeitiformis (DH)

Question 32

What is the treatment for DH?

Answer 32

gluten-free diet and dapsone (sulfa-based antibiotic)

Question 33

what are some common features of Dermatitis Herpetiformis (DH)?

Answer 33

affects individuals of northern descent Very itchy affects the occipital scalp, extensor upper and lower extremities and buttocks lesions are papules, vesicles, and urticarial plaques

Question 34

What cancer of DH patients at risk of contracting?

Answer 34

gastric lymphoma (6%)