Lichen planus

Question 1

Primary lesion in Lichen planus

Answer 1

small, shiny, polygonal, flat-topped violaceous papules +/- Wickhams striae (more apparent when lesions wet)

Question 2

Distribution of Lichen planus

Answer 2

Typically limited to a few areas (lower legs, flexor ankles and wrists, genitalia)

Question 3

Variant presentations of lichen planus

Answer 3

Bullous (bullae within pre-existing LP lesions)
LP pemphigoides
Actinic
Annular
Hypertrophic
Atrophic
Hemorrhagic/purpuric
Linear
Erosive/ulcerative
LP/Lupus erythematosus
Lichen planopilaris

Question 4

Drugs implicated in lichenoid drug rxn

Answer 4

antihypertensives (captopril, enalapril, labetalol, propranolol)
antimalarials
metals
diuretics (HCTZ)
penicilamine

Question 5

Time course to develop lichenoid drug eruption

Answer 5

Unlike other drug eruptions (w/in 1 mo), lichenoid typically takes several months to years

Question 6

Difference in appearance of classic LP and lichenoid drug eruption

Answer 6

Drug eruption tends to be more eczematous, psoriasiform, or PR like and much less commonly involve oral mucosa
More eosinophils on histology

Question 7

Erosive oral lichen planus

Answer 7

Has potential for malignant transformation (instruct pts to avoid tobacco)