Epidermolysis Bullosa

Epidermolysis Bullosa

Q. 1

The target antigen in dermolytic variant of epidermolysis bullosa is:

 A

Laminin 5

 B

Keratin 5 and 14

 C

Collagen 7

 D

Kindlin-1

Q. 1

The target antigen in dermolytic variant of epidermolysis bullosa is:

 A

Laminin 5

 B

Keratin 5 and 14

 C

Collagen 7

 D

Kindlin-1

Ans. C

Explanation:

Epidermolysis bullosa is classified into 4 types depending on the level of cleavage:

1. Epidermolytic variant : Keratin 5 & 14 (most common antigen)
2. Lamina lucida lytic : Laminin 5 (most common antigen)
3. Dermolytic variant : Type 7 collagen (most common antigen)
4. Mixed variant : Kindlin-1 (most common antigen)
 
Ref: Rook’s Textbook of Dermatology, 8th Edition, Page  39.2.

 


Q. 2

U-serrated pattern in direct immunofluorescence is seen in:

 A

Epidermolysis bullosa acquisita

 B

Bullous pemphigoid

 C

Linear IgA disease

 D

Dermatitis herpetiformis

Q. 2

U-serrated pattern in direct immunofluorescence is seen in:

 A

Epidermolysis bullosa acquisita

 B

Bullous pemphigoid

 C

Linear IgA disease

 D

Dermatitis herpetiformis

Ans. A

Explanation:

Epidermolysis bullosa acquisita: Direct immunofluorescence shows, linear IgG, Ig A, Ig M at the basement-membrane zone with diagnostic U-serrated pattern. Patients’ skin split through the lamina lucida with 1 mol/L salt demonstrates the IgG antibodies to be bound to the dermal aspect of the blister. N serrated pattern is seen in bullous pemphigoid. 

 
Ref: Rook’s textbook of dermatology, 8th edition, Pg 40.53.

Q. 3

Genetic predisposition is seen in which disease:

 A

Lichen planus

 B

Bullous pemphigoid

 C

Pemphigus vulgaris

 D

Epidermolysis Bullosa

Q. 3

Genetic predisposition is seen in which disease:

 A

Lichen planus

 B

Bullous pemphigoid

 C

Pemphigus vulgaris

 D

Epidermolysis Bullosa

Ans. D

Explanation:

D i.e. Epidermolysis bullosa


Q. 4

Etiology of Epidermolysis bullosa is ‑

 A

Genetic

 B

Infections

 C

Senile

 D

Malignant

Q. 4

Etiology of Epidermolysis bullosa is ‑

 A

Genetic

 B

Infections

 C

Senile

 D

Malignant

Ans. A

Explanation:

A. i.e. Genetic


Q. 5

In congenital dystrophic epidermolysis bullosa defect is seen in:

 A

Laminin 4

 B

Collagen type 7

 C

Collagen 4

 D

Collagen 3

Q. 5

In congenital dystrophic epidermolysis bullosa defect is seen in:

 A

Laminin 4

 B

Collagen type 7

 C

Collagen 4

 D

Collagen 3

Ans. B

Explanation:

B. i.e. Collagen 7


Q. 6

In a 8 day old child with no history of consanguinity in the parents. The mother reports blisters and peeling off of skin at the site of handling and pressure. There was a similar history in previous child which proved to be fatal. The diagnosis:

 A

Bullous pemphigod

 B

Conegntial Syphillis

 C

Congential Epidermolysis bullosa

 D

Letterrer siwe disease

Q. 6

In a 8 day old child with no history of consanguinity in the parents. The mother reports blisters and peeling off of skin at the site of handling and pressure. There was a similar history in previous child which proved to be fatal. The diagnosis:

 A

Bullous pemphigod

 B

Conegntial Syphillis

 C

Congential Epidermolysis bullosa

 D

Letterrer siwe disease

Ans. C

Explanation:

C i.e. Congenital Epidermolysis bullosa


Q. 7

A 2 day old newborn girl born out of non-consanguinous marriage was evaluated for tense blister and areas of denuded skin that had been present since birth. The child develops while mother handles for bathing and feeding. The sibling of child also had h/o developing similar lesions.

 A

Congenital syphilis

 B

Congenital epidermolysis bullosa

 C

LCH

 D

Congenital bullous icthyosiform erythroderma

Q. 7

A 2 day old newborn girl born out of non-consanguinous marriage was evaluated for tense blister and areas of denuded skin that had been present since birth. The child develops while mother handles for bathing and feeding. The sibling of child also had h/o developing similar lesions.

 A

Congenital syphilis

 B

Congenital epidermolysis bullosa

 C

LCH

 D

Congenital bullous icthyosiform erythroderma

Ans. B

Explanation:

B i.e. Congenital Epidermolysis bullosa


Q. 8

Mutation in which collagen is present in epidermolysis bullosa ‑

 A

II

 B

IV

 C

V

 D

VII

Q. 8

Mutation in which collagen is present in epidermolysis bullosa ‑

 A

II

 B

IV

 C

V

 D

VII

Ans. D

Explanation:

Ans. is ‘d’ i.e., VII 

Molecular pathology of EB

  • Normal basement membrane is between epidermal basal layer and dermis. This basement membrane (basal lamina) is attached to basal cells hemidesmosomes with the help of keratin containing intermediate filaments and is attached to dermis (dermal papillary layer) with the help of type VII collegen containing fibrils. Any defect in this anchoring complex leads to separation of skin; the site of separation depends on the type of defect
  1. EB simplex —> Mutation in gene coding for keratin 5 & 14 (major keratin of BMZ) and separation will be epidermal.
  2. EB junctional —> Mutation in Lantinin a-3 (LAM a-3), LAM [I-3, LAM 7-2 genes. As laminin is part of basement membrane the separation will be at dermo-epidermal junction (DEJ).
  3. EB dystrophicans —> Mutation in collagen VII-Al gene. As collagen VII containing fibrils join BM to dermal papilla, separation will be in the dermis.
  • Any of the above defect results in defective cohesiveness which leads to vulnerability to trauma and blisters formation. As the disease is inherited, Family history may be positive.

Q. 9

A 5 year old girl presented with recurrent skin lesions  over the body as shown in the image following trivial trauma.What can be the most possible diagnosis?

 A

Dermatitis Herpetiformis

 B

Epidermolysis Bullosa

 C

Bullous Pemphigoid

 D

Pemphigous Vulgaris

Q. 9

A 5 year old girl presented with recurrent skin lesions  over the body as shown in the image following trivial trauma.What can be the most possible diagnosis?

 A

Dermatitis Herpetiformis

 B

Epidermolysis Bullosa

 C

Bullous Pemphigoid

 D

Pemphigous Vulgaris

Ans. B

Explanation:

Ans:B.)Epidermolysis Bullosa.

Epidermolysis Bullosa

Epidermolysis bullosa (EB) is a group of inherited bullous disorders characterized by blister formation in response to trivial mechanical trauma.
Pathophysiology:

  • Epidermolysis bullosa is a family of bullous disorders caused by an absence of basement membrane components due to underlying gene mutations. Epidermolysis bullosa is classified into three major categories: (1) epidermolysis bullosa simplex (intraepidermal skin separation), (2) junctional epidermolysis bullosa (skin separation in lamina lucida or central BMZ), and (3) dystrophic epidermolysis bullosa (sublamina densa BMZ separation).
  •  

    Junctional epidermolysis bullosa: minor trauma
    has caused large blisters and erosions which will heal
    slowly or not at all.

       

  • Autosomal recessive dystrophic epidermolysis
    bullosa: note large blood-filled blister. Scarring has led to
    fixed deformity of the fingers and loss of nails.



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