Inflammatory Dermatoses Flashcards

The classic clinical description of lichen planus is remembered by the 'six Ps.' Which set correctly lists them?

Answer: Pruritic, purple, polygonal, planar, papules, plaques

Lichen planus lesions are pruritic, purple, polygonal, planar (flat-topped) papules and plaques.

The fine white reticulated network overlying lichen planus papules and oral mucosa is called what?

Answer: Wickham striae

Wickham striae are the lacy white lines seen on lichen planus lesions and oral involvement.

Histology of lichen planus classically shows a band-like lymphocytic infiltrate at the dermoepidermal junction with what saw-tooth change?

Answer: Sawtooth acanthosis of the rete ridges

Lichen planus shows a dense band-like (lichenoid) infiltrate with sawtooth rete ridges and hypergranulosis.

A lichenoid drug eruption resembling lichen planus is commonly caused by which class of medications?

Answer: Thiazide diuretics and ACE inhibitors

Thiazides, ACE inhibitors, antimalarials, and beta-blockers are classic causes of lichenoid drug eruptions.

Erosive oral lichen planus carries a small but real risk of transforming into which malignancy?

Answer: Squamous cell carcinoma

Chronic erosive oral lichen planus has a documented low risk of progression to squamous cell carcinoma.

Colloid (Civatte) bodies seen in lichen planus represent what?

Answer: Apoptotic (necrotic) keratinocytes

Civatte bodies are apoptotic basal keratinocytes found in lichenoid interface dermatitis.

Lichen planopilaris is a variant of lichen planus that leads to which outcome on the scalp?

Answer: Scarring (cicatricial) alopecia

Lichen planopilaris causes permanent scarring alopecia by destroying hair follicle stem cells.