Vacuolar interface dermatitis

Vacuolar interface dermatitis (VAC, also known as liquefaction degeneration, vacuolar alteration or hydropic degeneration) is a dermatitis with vacuolization at the dermoepidermal junction, with lymphocytic inflammation at the epidermis and dermis.

[1] An interface dermatitis with vacuolar alteration, not otherwise specified, may be caused by viral exanthems, phototoxic dermatitis, acute radiation dermatitis, erythema dyschromicum perstans, lupus erythematosus and dermatomyositis.

[2]

Vacuolar interface dermatitis, with lymphocytes in the dermis and epidermis (black arrow indicates one), and vacuolization (white arrow) at the dermoepidermal junction .
Micrograph of a vacuolar interface dermatitis with dermal mucin, as may be seen in lupus . H&E stain .