9 - 57 - IGA PEMPHIGUS

Question 1

autoantibodies play a pathogenic role in SPD-type IAD

Answer 1

IgA anti-Dsc1

Question 2

desmocollin subtype expressed in the keratinocyte cell surfaces in the uppermost epidermis, where subcorneal pustules and IgA deposition are found in the skin lesions of SPD-type IAD

Answer 2

Dsc1

Question 3

Dsc expressed in the entire epidermis

Answer 3

Dsc2

Question 4

Dsc expressed more strongly in the low epidermis

Answer 4

Dsc3

Question 5

clinical manifestations of SPD-type IAD

Answer 5

• Superficial flaccid pustules in the periphery of annular of herpetiform erythemas
• Most prominent in axillae and groin
• Most pustular skin lesions turn into erosions and crusts resulting in PIH
• indistinguishable from those seen in patients with classical SPD without IgA autoantibodies
• (-) Nikolsky
• Never develops mucosal membrane lesions

Question 6

clinical manifestations of IEN-type IAD

Answer 6

• Demarcated atypical pustular lesions scattered on entire body;
  *** “Sunflower like” configuration: **relatively deep pustules develop on the slightly elevated periphery of annular erythemas of 10 mm to 30 mm
• May have mucosal involvement

Question 7

develop PVeg-like vegetating skin lesions with erosions, prevalently in the intertriginous areas and the scalp

Answer 7

PVeg-type IAD

Question 8

Underlying disease most frequently found in IAD

Answer 8

ulcerative colitis

Question 9

other diseases associated with IAD aside from ulcerative colitis

Answer 9

multiple myeloma or B-cell lymphoma

Question 10

ulcerative colitis is associated with either IEN-type IAD or PV-type IAD, but never with what subtype?

Answer 10

SPD-type IAD

Question 11

preferred test for detecting IgA reactivity with Dsc1, Dsc2, and Dsc3 in various types of IAD

Answer 11

IgA ELISA using mammalian recombinant proteins

Question 12

course and prognosis of IAD

Answer 12

• IAD has a much better prognosis and is rarely fatal
• In general, IAD patients can be controlled with dapsone with or without low doses of systemic corticosteroids
• disease course is usually refractory, and skin lesions frequently recur upon withdrawal of the drugs
• IAD is considered to be not fatal disease but extremely intractable disease condition

Question 13

second choice of therapy in IAD

Answer 13

• Prednisolone 0.2 to 0.5 mg/ kg/day (low-dose

Question 13

most common therapy in IAD

Answer 13

• Dapsone 50 to 200 mg/day