Pemphigus vulgaris

Bullous cutaneous diseases are characterized by the presence of a bulla, a neoformed cavity, which may be located within or below the epidermis. A bulla can form due to acantholysis (loss of cohesion by cells of the spinous layer) or to a detachment of the epidermal from the dermis. Bullous cutaneous diseases are numerous, therefore an accurate clinical and histological differential diagnosis is necessary.

Pemphigus is a rather frequent bullous dermatitis, in which the bulla is formed by acantholysis. There are several variants of pemphigus: pemphigus vulgaris, pemphigus vegetans, pemphigus foliaceus, and pemphigus erythematous. Pemphigus vulgaris is an autoimmune disease with flaccid bullae, which break easily and leave denuded areas that tend to increase in size. The bulla of pemphigus vulgaris is acantholytic and cells are found free in the cavity. Tipically, acantholysis is suprabasal; therefore, the basal layer remains intact and forms the floor of the bulla. In pemphigus foliaceus acantholysis occurs at a higher level, involving the granular layer; the disease is characterized by large flaccid bullae, which break and leave shallow erosions, rather than denuded areas as in pemphigus vulgaris.

Bullous pemphigoid shows large tense bullae, which, when they break, result in denuded areas. Such denuded areas, however, do not tend to increase in size as they do in pemphigus vulgaris; rather they tend to heal. In pemphigoid the bulla is subepidermal, therefore, the floor of the bulla is formed by the dermis with no epithelial lining. Within the neoformed cavity fibrin and inflammatory cells (expecially eosiniphils) are found.

Dermatitis herpetiformis is a pruritic, chronic disease, showing symmetric groups of papules, vescicles or, rarely, bullae, surrounded by erythema (extensor surfaces of the extremities, shoulders, buttocks). Histologically, early lesions show neutrophilic microabscesses at the tips of adjoining papillae; then a vescicle or a bulla may occur; bulla is subepidermal with neutrophils.

Other bullous cutaneous diseases are: herpes gestationis, observed in pregnancy or in puerperium, shows vescicles, bullae, erythema and severe itching; epidermolysis bullosa, which shows subepidermal bullae and no inflammatory infiltrate; linear IgA bullous dermatosis, occurring in childooh, which shows subepidermal bullae and granular deposits of IgA at the dermoepidermal junction (immunofluorescence test).

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The other pages

Home Page: Dermatopathology - C. Urso, MD

page 1: Melanoma of the skin

page 2: Histologic diagnosis of cutaneous melanoma

page 3: Melanoma arising in a melanocytic nevus

page 4: Infiltration and pseudoinfiltration

page 5: Sweat gland carcinomas

page 6: The sentinel lymph node in cutaneous melanoma

page 7: Bullous cutaneous diseases

page 8: Spitz nevus

page 9: Prognostic factors in cutaneous melanoma

page 10: The dysplastic nevus

page 11: Dermatofibrosarcoma protuberans

page 12: Melanoma in situ
page 13: Merkel cell carcinoma
page 14: Basal cell carcinoma
page 15: Melanoma in paediatric age

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