Type 2 Hypersensitivities - Pemphigoids

Question 1

Read the following information and then name the dermatologic condition that it represents and why.

“Multiple tense bullae, excoriated papules, and vesicles ranging in size from a few millimeters to 3 cm over her right hand and arm, anterior chest, and abdomen. The bullae contain clear fluid. No involvement of the oral or vulvar mucous membranes is seen, and the Nikolsky sign is not elicited.”

Answer 1

Bullous pemphigoid

• Nikolsky sign absent
• No mucous membrane involvement

Question 2

What skin condition is shown by this image?

Answer 2

Bullous pemphigoid

Question 3

What cells are seen in the image indicated by the grey line?

Answer 3

Immune cells (eosinophils)

Question 4

The following images show direct immunofluorescence for IgG and C3b. Explain the findings.

Answer 4

This is direct, so the test would have introduced a mab with conjugated fluorophore for either IgG or C3b. The areas of intense green show where IgG and C3b are found in the skin of a patient with bullous pemphigoid.

Question 5

This is showing an indirect immunofluorescence test. Explain what the image shows.

Answer 5

The skin in this case is from a person who does not have bullous pemphigoid. The dermis and epidermis were separated with salt. The serum from a patient with BP would have been run over this skin sample and then a second mab that detected IgG was introduced with fluorophore. The purpose is to see where in the skin the person’s antibodies are attacking.

Question 6

What is the protein that the body attacks with autoantibodies in bullous pemphigoid?

Answer 6

The image below is a zoom in of the proteins that anchor cells of the stratum basale to the basement membrane through hemidesmosomes. Thus, BP is a disease where autoantibodies attack hemidesmosomes.

Question 7

What dermatologic pemphigoid conditio is shown in these images?

Answer 7

Pemphigus vulgaris –> autoantibodies against desmoglein 3 which is located in lower layers of the stratum spinosum

Positive nikolsky sign –> because the deformity is more superficial acutally able to remove skin with shear force

Question 8

What dermatologic pemphigoid condition is shown by these images?

Answer 8

Pemphigus foliaceus –> autoantibodies against desmoglein 1 which is in desmosomes in higher layers of the epidermis

Positive Nikolsky sign