S4C16aP8a-1: In this patient, the clinical manifestations of disease progressed from the picture of erythema multiforme to toxic epidermal necrolysis. Histologically, the patterns are those of a cytopathic process affecting the basal layer and, in areas, the basal unit of the epidermis. Necrotic keratinocytes are spaced along the basement membrane zone;  focally, they are clustered in defects at the dermal-epidermal interface. The reaction is rather cell-poor with perivascular infiltrates and with linear infiltrates of lymphocytes and histiocytes at the dermal-epidermal interface. The keratin layer is unaffected. The patterns are erythema multiforme-like.

S4C16aP8a-2: The histologic markers are those of a lichenoid reaction of erythema multiforme-like type. In this field, the epidermis has separated from the dermis to form a subepidermal defect. The roof of the bulla shows extensive necrosis of cells in the basal unit of the epidermis. Lymphocytes intermingle among the necrotic keratinocytes. Some of the cells in the superficial unit of the epidermis show ballooning degeneration. The keratin layer is normal. The inflammatory infiltrates in the papillary dermis are mild.

S4C16aP8a-3: In the roof of the bulla, necrotic keratinocytes are prominent in the epidermal domain of what once would have been the basal unit. The superficial unit of the roof shows individual, and clustered, balloon cells. To the right along the plane between viable and necrotic keratinocytes, a nucleus contains an inclusion. In this patient, there was a history suggesting a bout of herpes simplex prior to the onset of the bullous disorder.

Back one CHAPTER

Next CHAPTER

Up to next tier

Note: movements with the above buttons are spatial rather than temporal