ABD Inflammatory Dermatoses 3 — Questions and Answers
Question 1: The classic clinical description of lichen planus is remembered by the 'six Ps.' Which set correctly lists them?
- Pruritic, purple, polygonal, planar, papules, plaques (Correct answer)
- Painful, pale, patchy, peeling, papules, pustules
- Pruritic, pink, round, raised, papules, nodules
- Painless, purple, linear, scaly, plaques, vesicles
Correct answer: Pruritic, purple, polygonal, planar, papules, plaques
Lichen planus lesions are pruritic, purple, polygonal, planar (flat-topped) papules and plaques.
Question 2: The fine white reticulated network overlying lichen planus papules and oral mucosa is called what?
- Wickham striae (Correct answer)
- Munro microabscesses
- Auspitz sign
- Herald patch
Correct answer: Wickham striae
Wickham striae are the lacy white lines seen on lichen planus lesions and oral involvement.
Question 3: Histology of lichen planus classically shows a band-like lymphocytic infiltrate at the dermoepidermal junction with what saw-tooth change?
- Sawtooth acanthosis of the rete ridges (Correct answer)
- Suprabasal acantholysis
- Subepidermal blister
- Follicular plugging only
Correct answer: Sawtooth acanthosis of the rete ridges
Lichen planus shows a dense band-like (lichenoid) infiltrate with sawtooth rete ridges and hypergranulosis.
Question 4: A lichenoid drug eruption resembling lichen planus is commonly caused by which class of medications?
- Thiazide diuretics and ACE inhibitors (Correct answer)
- Topical retinoids
- Oral antihistamines
- Calcium supplements
Correct answer: Thiazide diuretics and ACE inhibitors
Thiazides, ACE inhibitors, antimalarials, and beta-blockers are classic causes of lichenoid drug eruptions.
Question 5: Erosive oral lichen planus carries a small but real risk of transforming into which malignancy?
- Squamous cell carcinoma (Correct answer)
- Basal cell carcinoma
- Melanoma
- Merkel cell carcinoma
Correct answer: Squamous cell carcinoma
Chronic erosive oral lichen planus has a documented low risk of progression to squamous cell carcinoma.
Question 6: Colloid (Civatte) bodies seen in lichen planus represent what?
- Apoptotic (necrotic) keratinocytes (Correct answer)
- Neutrophil aggregates
- Mast cell granules
- Dermal mucin deposits
Correct answer: Apoptotic (necrotic) keratinocytes
Civatte bodies are apoptotic basal keratinocytes found in lichenoid interface dermatitis.
Question 7: Lichen planopilaris is a variant of lichen planus that leads to which outcome on the scalp?
- Scarring (cicatricial) alopecia (Correct answer)
- Non-scarring diffuse shedding
- Seborrheic dermatitis
- Reversible telogen effluvium
Correct answer: Scarring (cicatricial) alopecia
Lichen planopilaris causes permanent scarring alopecia by destroying hair follicle stem cells.
ABD Inflammatory Dermatoses 3
The classic clinical description of lichen planus is remembered by the 'six Ps.' Which set correctly lists them?