Acute and Chronic Dermatosis (Inflammation)

Question 1

What skin abnormalities fall under acute dermatoses?

Answer 1

Urticaria (Hives)
Eczema
Erythema multiforme

Question 2

What is an acute dermatoses?

Answer 2

• Lesions lasts days to weeks
• Characterized by:
  # Inflammatory infiltrate
  # Edema
  # Epidermal/vascular/subcutaneous injury

Question 3

What skin abnormalities fall under chronic dermatoses?

Answer 3

Psoriasis
Seborrheic dermatitis
Lichen Planus
Lupus erythematosus

Question 4

What is chronic dermatoses?

Answer 4

• Lesions persists months to years
• Characterized by:
  # Epidermal atrophy/hyperplasis or
  # Dermal fibrosis.

Question 5

What is Urticaria?

Answer 5

Pruritic inflammation of the skin > “hives”

Characterized by > superficial, localized edema and erythema

Question 6

What lesions are found in Urticaria?

Answer 6

Wheals due to dermal microvascular hyper permeability

Plaque & Papule > can coalesce to form annular/linear/arciform configurations

Question 7

How does the wheal look like?

Answer 7

erythematous , edematous and pruritic

Question 8

How is Urticaria mediated?

Answer 8

By localized mast cell degranulation

Question 9

What does the degranulation of mast cells lead to?

Answer 9

1) Dilatation of vascular spaces, dermal microvascular hyperpermiability > Dermal oedema( wheals)
2) Early perivascular cuffing of inflammatory cell > pruritic papules

Question 10

Describe Pathogenesis of Urticaria

Answer 10

1) Antigen > presented to B & TH2 cells > IgE production
2) IgE binds to Fc receptors on mast cells, and upon repeated exposure to the antigen/allergen, mast cells gets activated & secrete mediators (ECF, NCF, PAF)
(Refer to slide 24 & 25)

Question 11

What is the type of Hypersensitivity in Urticaria?

Answer 11

Type 1 Hypersensitivity

Question 12

What are the three clinical forms of URTICARIA?

Answer 12

1) IgE- Dependent Urticaria
2) IgE- Independent Urticaria
3) Complement Mediated Urticaria = Hereditary Angioneurotic Edema ( HAE)