Pityriasis lichenoides

Question 1

Both PLEVA and PLC are characterized by the clinical findings of:

Answer 1

• recurrent crops of self-resolving lesions

Question 2

Etiology of PLEVA/PLC?

Answer 2

• unclear, may represent response to infections/drugs, or may represent low grade T-cell lymphoproliferative disorder

Question 3

PLEVA has ____ onset of lesions .

Answer 3

• rapid onset

Question 4

Where does PLEVA tend to occur on body?

Answer 4

• widespread (trunk, buttock, and proximal extremities> other sites)

Question 5

Describe the primary lesions of PLEVA

Answer 5

• pink papule that turn into vesicles, can necrose/become purpuric

Question 6

How do lesions of PLEVA heal?

Answer 6

• with varioliform scars! (Varioliformis)

Question 7

_____ is a variant of PLEVA and presents with systemic systems including _____

Answer 7

• Febrile ulceronecrotic Mucha-Haberman disease
• FUMH has PLEVA
• High fever, constitutional symptoms, LAD, arthritis, mucosal, pulmonary and GI involvement.

Question 8

Febrile ulceronecrotic Mucha-Haberman disease (PLEVA variant) is a/w increased _____ levels

Answer 8

• increased TNF alpha levels

Question 9

Pityriasis lichenoides chronic presents with:

Answer 9

• widespread, red-brown, scaly papule and plaques

Question 10

PLC resolves with _____ whereas PLEVA resolves with ____

Answer 10

• hypopigmentation

- varioliform scars

Question 11

Which occurs more frequently in adults, PLC or PLEVA

Answer 11

PLC>PLEVA in adults (adults are chronic)

Question 12

Histology of PLEVA:

Answer 12

PLEVA: P- Parakeratosis
L- Lichenoid infiltrate
E- Extravasation of RBC’s
V- V-shaped dermal lymphocytic infiltrate
A- Acute epidermal changes (dyskeratosis, ulceration, neutrophilic scale crust)

Question 13

Histology of PLC:

Answer 13

similar to PLEVA, but MORE SUBTLE
P- Parakeratosis
L- Lichenoid infiltrate
E- Extravasation of RBC’s
V- V-shaped dermal lymphocytic infiltrate
A- Acute epidermal changes (dyskeratosis, ulceration, neutrophilic scale crust)

Question 14

Histology of PLEVA and PLC both have strict absence of______.

What is another interface dermatitis that does not have these (in most subtypes)

Answer 14

• eosinophils!!!!!!

- Lichen Planus does not have eos, unless its drug induced or hypertrophic forms

Question 15

First line of tx for PLEVA and PLC

Answer 15

• topical steroids, phototherapy, systemic antibiotics (erythromycin, azithromycin)

Question 16

Severe forms of PLEVA/PLC can be treated with:

Answer 16

• if severe, can use MTX, cyclosporine, and IVIG

Question 17

What is the best predictor for speed of disease resolution for PLEVA/PLC?

Answer 17

• distribution of disease

Question 18

Which distribution of PLEVA/PLC resolves fastest, slowest, in between?

Answer 18

• diffuse distribution resolves fastest (11 months on average)
• slowest is peripheral distribution (33 months on average)
• central distribution in between

Question 19

In PLEVA/PLC, _____ predominate within the infiltrate which helps distinguish from majority of other conditions in the differential.

Answer 19

• CD8+ t-cells!!!