Grade

Histologic Features (Acute Phase)

I.

Vacuolar alteration of the basal layers (basal layer liquefaction), focal or diffuse.

II.

Epidermal dyskeratotic or necrotic keratinocytes occasionally surrounded by lymphocytes (satellite necrosis)

III.

More widespread necrosis of keratinocytes with separation at the dermoepidernal junction.

IV.

Full thickness necrosis and loss of epidermis.

Chronic Phase

Histologic Features (Chronic Phase)

Lichenoid phase

Compact hyperkeratosis, irregular epidermal hyperplasia with saw-tooth appearance, band-like lymphocytic in the superficial dermis obscuring the dermoepidermal junction (interface dermatitis), eosinophilic colloid bodies (Civatte bodies) at dermoepidermal junction.

Sclerotic phase

changes similar to dermal sclerosis extending into subcutaneous fat and loss of adnexal structures with marked epidermal atrophy